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| [[File:Keylogger-screen-capture-example.png|thumb|A keylogger example of a screencapture, which holds potentially confidential and private information. This is the corresponding text result of the keylogger: http://commons.wikimedia.org/wiki/File:Keylogger-software-logfile-example.jpg]]
| | Frank just what her husband loves to call her but she doesn't like when people use her full nickname. Bookkeeping is what I. My husband and I chose to reside in Nebraska however, now I'm considering other types. My wife doesn't although you may the way I do but a few things i really look foward to is [http://Photobucket.com/images/solving+puzzles solving puzzles] nevertheless i [http://Imageshack.us/photos/struggle struggle] get time for it. I've been working on the website relatively time at once. Check it out here: https://vimeo.com/91911014<br><br>My web site; Catalina Porn ([https://vimeo.com/91911014 just click the following web site]) |
| '''Keystroke logging''', often referred to as '''keylogging''' or '''Keyboard Capturing''', is the action of recording (or logging) the keys struck on a [[keyboard (computing)|keyboard]], typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored.<ref>{{cite web|url=http://oxforddictionaries.com/definition/english/keylogger|publisher=Oxford dictionaries |title=Keylogger}}</ref> It also has very legitimate uses in studies of human-computer interaction. There are numerous keylogging methods, ranging from hardware and software-based approaches to [[acoustics|acoustic]] analysis.
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| == Application ==
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| === Software-based keyloggers ===
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| [[File:Keylogger-software-logfile-example.jpg|thumb|A [[logfile]] from a software-based keylogger.]]
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| These are computer programs designed to work on the target computer's [[operating system]].<ref>{{cite web|title=What is a Keylogger?|url=http://www.pctools.com/security-news/what-is-a-keylogger/|publisher=PC Tools}}</ref> From a technical perspective there are five categories:
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| * '''Hypervisor-based''': The keylogger can theoretically reside in a [[malware]] [[hypervisor]] running underneath the operating system, which remains untouched. It effectively becomes a [[virtual machine]]. [[Blue Pill (software)|Blue Pill]] is a conceptual example.
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| * '''[[Kernel (computing)|Kernel]]-based''': This method is difficult both to write and to combat. Such keyloggers reside at the [[Ring (computer security)|kernel level]] and are thus difficult to detect, especially for user-mode applications. They are frequently implemented as [[rootkit]]s that subvert the operating system kernel and gain unauthorized access to the hardware, making them very powerful. A keylogger using this method can act as a keyboard [[device driver]] for example, and thus gain access to any information typed on the keyboard as it goes to the operating system.
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| * '''API-based''': These keyloggers [[Hooking|hook]] keyboard [[Application programming interface|APIs]]; the operating system then notifies the keylogger each time a key is pressed and the keylogger simply records it. Windows APIs such as <code>GetAsyncKeyState()</code>, <code>GetForegroundWindow()</code>, etc. are used to poll the state of the keyboard or to subscribe to keyboard events.<ref>{{cite journal|url=http://www.symantec.com/avcenter/reference/the.evolution.of.malicious.irc.bots.pdf|publisher=[[Symantec]]|date=2005-11-26|title=The Evolution of Malicious IRC Bots|accessdate=2011-03-25|pages=23–24}}</ref> These types of keyloggers are the easiest to write, but where constant polling of each key is required, they can cause a noticeable increase in [[Central processing unit|CPU]] usage, and can also miss the occasional key. A more recent example simply polls the [[BIOS]] for pre-boot authentication [[Personal identification number|PIN]]s that have not been cleared from memory.<ref>{{cite journal|url=http://www.ivizsecurity.com/research/preboot/preboot_whitepaper.pdf|format=PDF|title=Bypassing pre-boot authentication passwords by instrumenting the BIOS keyboard buffer (practical low level attaks against x86 pre-boot authentiation software)|date=2008-09-03|accessdate=2008-09-23|author=Jonathan Brossard|publisher=[http://www.ivizsecurity.com Iviz Technosolutions]}}</ref>
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| * '''Form grabbing based''': [[Form grabbing]]-based keyloggers log [[Form (web)|web form]] submissions by recording the web browsing onsubmit event functions. This records form data before it is passed over the Internet and bypasses [[HTTP Secure|HTTPS]] encryption.
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| * '''Memory injection based''': Memory Injection ([[Man-in-the-browser|MitB]])-based keyloggers alter memory tables associated with the browser and other system functions to perform their logging functions. By patching the memory tables or injecting directly into memory, this technique can be used by malware authors who are looking to bypass Windows UAC (User Account Control). The Zeus and Spyeye Trojans use this method exclusively.<ref>{{cite news|title=SpyEye Targets Opera, Google Chrome Users|url=https://krebsonsecurity.com/2011/04/spyeye-targets-opera-google-chrome-users/|accessdate=26 APR 11|newspaper=Krebs on Security}}</ref>
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| * '''[[Packet sniffing|Packet analyzers]]''': This involves capturing network traffic associated with [[POST (HTTP)|HTTP POST]] events to retrieve unencrypted passwords.
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| Remote access software keyloggers
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| These are local software keyloggers with an added feature that allows access to the locally recorded data from a remote location. Remote communication may be achieved using one of these methods:
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| * Data is uploaded to a website, database or an [[File Transfer Protocol|FTP]] server.
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| * Data is periodically emailed to a pre-defined [[email address]].
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| * Data is [[wireless]]ly transmitted by means of an attached hardware system.
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| * The software enables a remote login to the local machine from the Internet or the local network, for data logs stored on the target machine to be accessed.
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| ==== Keystroke logging in Writing Process Research ====
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| Keystroke logging has become an established research method to study writing processes.<ref>K.P.H. Sullivan & E. Lindgren (Eds., 2006), Studies in Writing: Vol. 18. Computer Key-Stroke Logging and Writing: Methods and Applications. Oxford: Elsevier.</ref><ref>V. W. Berninger (Ed., 2012), Past, present, and future contributions of cognitive writing research to cognitive psychology. New York/Sussex: Taylor & Francis. [ISBN 9781848729636]</ref> Different programs have been developed to collect online process data of writing activities.<ref name=AAA>{{cite news |url= http://www.spywareloop.com/news/keystroke-logging|title= Keystroke Logging in SpyWareLoop.com|author= Vincentas |newspaper=''Spyware Loop'' |date=11 July 2013 |accessdate=27 July 2013}}</ref> The most common{{citation needed|date=June 2013}} are: [[Inputlog]],<ref>[http://www.inputlog.net inputlog.net]</ref> Scriptlog,<ref>[http://scriptlog.no/ scriptlog.no]</ref> and Translog.<ref>[http://www.translog.dk/ translog.dk]</ref> Most of these programs have overlapping capabilities, but all of them have also very specific characteristics making them complementary in their use.
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| Keystroke logging can be a suitable research instrument in a number of writing contexts. Research areas include for instance the following: studies on cognitive writing processes in general, description of writing strategies in professional writing or creative writing, the writing development of children with and without writing difficulties, spelling, first and second language writing, and the writing of expert and novice writers in professional contexts and in specialist skill areas such as translation and subtitling. Not only can keystroke logging be used in research specifically on writing, it can also be integrated in educational domains for second language learning, programming skills, and typing skills.
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| ==== Related features ====
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| Software keyloggers may be augmented with features that capture user information without relying on keyboard key presses as the sole input. Some of these features include:
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| * Clipboard logging. Anything that has been copied to the [[Clipboard (software)|clipboard]] can be captured by the program.
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| * Screen logging. [[Screenshot]]s are taken in order to capture graphics-based information. Applications with screen logging abilities may take screenshots of the whole screen, just one application or even just around the mouse cursor. They may take these screenshots periodically or in response to user behaviours (for example, when a user has clicked the mouse). A practical application used by some keyloggers with this screen logging ability is to take small screenshots around where a mouse has just clicked; these defeat web-based keyboards (for example, the web-based screen keyboards that are often used by banks) and any web-based on-screen keyboard without screenshot protection.
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| * Programmatically capturing the text in a [[GUI widget|control]]. The [[Microsoft Windows]] [[Application programming interface|API]] allows programs to request the text 'value' in some controls. This means that some passwords may be captured, even if they are hidden behind password masks (usually asterisks).<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/bb761584(VS.85).aspx|author=Microsoft|title=EM_GETLINE Message()|accessdate=2009-07-15|publisher=[[Microsoft]]}}</ref>
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| * The recording of every program/folder/window opened including a screenshot of each and every website visited, also including a screenshot of each.
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| * The recording of [[Web search query|search engines queries]], [[instant messenger]] conversations, FTP downloads and other Internet-based activities (including the bandwidth used).
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| === Hardware-based keyloggers ===
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| [[File:Keylogger-hardware-PS2.jpg|thumb|A hardware-based keylogger.]]
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| [[File:Keylogger-hardware-PS2-example-connected.jpg|thumb|A connected hardware-based keylogger.]]
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| {{Main|Hardware keylogger}}
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| Hardware-based keyloggers do not depend upon any software being installed as they exist at a hardware level in a computer system.
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| * Firmware-based: [[BIOS]]-level [[firmware]] that handles keyboard events can be modified to record these events as they are processed. Physical and/or [[Superuser|root-level access]] is required to the machine, and the software loaded into the BIOS needs to be created for the specific hardware that it will be running on.<ref>{{cite web|title=Apple keyboard hack|url=http://www.digitalsociety.org/2009/08/apple-keyboards-hacked-and-possessed/|work=Apple keyboard hack|publisher=Digital Society|accessdate=9 June 2011}}</ref>
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| * Keyboard hardware: Hardware keyloggers are used for keystroke logging by means of a hardware circuit that is attached somewhere in between the [[computer keyboard]] and the computer, typically inline with the keyboard's cable connector. The are also [[Universal Serial Bus|USB]] connectors based Hardware keyloggers as well as ones for Laptop computers. the Mini-PCI card plugs into the expansion slot of a laptop. More stealthy implementations can be installed or built into standard keyboards, so that no device is visible on the external cable. Both types log all keyboard activity to their [[Primary storage|internal memory]], which can be subsequently accessed, for example, by typing in a secret key sequence.<ref>{{cite web|url=http://www.keyghost.com/sx/|title=Keyghost|accessdate=2009-04-19|publisher=[http://keyghost.com keyghost.com]}}</ref> A hardware keylogger has an advantage over a software solution: it is not dependent on being installed on the target computer's operating system and therefore will not interfere with any program running on the target machine or be detected by any [[Spyware#Anti-spyware programs|software]]. However its physical presence may be detected if, for example, it is installed outside the case as an inline device between the computer and the keyboard. Some of these implementations have the ability to be controlled and monitored remotely by means of a wireless communication standard.<ref>{{cite web|title=Keylogger Removal|url=http://spyreveal.com/keyloggerremoval|work=Keylogger Removal|publisher=SpyReveal Anti Keylogger|accessdate=25 April 2011}}</ref>
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| *Wireless keyboard sniffers: These passive sniffers collect packets of data being transferred from a wireless keyboard and its receiver. As encryption may be used to secure the wireless communications between the two devices, this may need to be cracked beforehand if the transmissions are to be read.
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| *Keyboard overlays: Criminals have been known to use keyboard overlays on [[Automated teller machine|ATMs]] to capture people's PINs. Each keypress is registered by the keyboard of the ATM as well as the criminal's keypad that is placed over it. The device is designed to look like an integrated part of the machine so that bank customers are unaware of its presence.<ref>{{cite news|url=http://www.pcworld.com/article/155525/.html?tk=rss_news|title=Tampered Credit Card Terminals|author=Jeremy Kirk|publisher=[[IDG]] News Service|date=2008-12-16|accessdate=2009-04-19}}</ref>
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| *Acoustic keyloggers: [[Acoustic cryptanalysis]] can be used to monitor the sound created by someone typing on a computer. Each key on the keyboard makes a subtly different acoustic signature when struck. It is then possible to identify which keystroke signature relates to which keyboard character via [[Statistics|statistical methods]] such as [[frequency analysis]]. The repetition frequency of similar acoustic keystroke signatures, the timings between different keyboard strokes and other context information such as the probable language in which the user is writing are used in this analysis to map sounds to letters.<ref>{{cite web|url=http://www.inf.ed.ac.uk/publications/thesis/online/IM100855.pdf|author=Andrew Kelly|title=Cracking Passwords using Keyboard Acoustics and Language Modeling|date=2010-09-10}}</ref> A fairly long recording (1000 or more keystrokes) is required so that a big enough [[sample (statistics)|sample]] is collected.<ref>[http://www.berkeley.edu/news/media/releases/2005/09/14_key.shtml Berkeley.edu]</ref>
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| *Electromagnetic emissions: It is possible to capture the [[Electromagnetic radiation|electromagnetic emissions]] of a wired keyboard from up to {{Convert|20|m|ft}} away, without being physically wired to it.<ref>{{cite news|url=http://news.zdnet.co.uk/security/0,1000000189,2082190,00.htm|title=Remote monitoring uncovered by American techno activists|publisher=[[ZDNet]]|date=2000-10-26|accessdate=2008-09-23}}</ref> In 2009, Swiss researchers tested 11 different [[Universal Serial Bus|USB]], [[IBM Personal System/2|PS/2]] and laptop keyboards in a semi-[[anechoic chamber]] and found them all vulnerable, primarily because of the prohibitive cost of adding [[Electromagnetic shielding|shielding]] during manufacture.<ref>{{cite journal|url=http://infoscience.epfl.ch/record/140523?ln=en|title=Compromising Electromagnetic Emanations of Wired and Wireless Keyboards|date=2009-06-01|author=Martin Vuagnoux and Sylvain Pasini|publisher=Security and Cryptography Laboratory (LASEC)|location=[[Lausanne]]}}</ref> The researchers used a wide-band [[Receiver (radio)|receiver]] to tune into the specific frequency of the emissions radiated from the keyboards.
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| *Optical surveillance: Optical surveillance, while not a keylogger in the classical sense, is nonetheless an approach that can be used to capture passwords or PINs. A strategically placed camera, such as a hidden [[surveillance camera]] at an [[Automated teller machine|ATM]], can allow a criminal to watch a PIN or password being entered.<ref>{{cite web|url=http://www.snopes.com/fraud/atm/atmcamera.asp|title=ATM camera|publisher=[http://snopes.com snopes.com]|accessdate=2009-04-19}}</ref>
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| *Physical evidence: For a keypad that is used only to enter a security code, the keys which are in actual use will have evidence of use from many fingerprints. A passcode of four digits, if the four digits in question are known, is reduced from 10,000 possibilities to just 24 possibilities ( <math>10^4</math> versus <math>4!</math> ). These could then be used on separate occasions for a manual "brute force attack".
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| == History ==
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| An early keylogger was written by [[Perry Kivolowitz]] and posted to the Usenet news group net.unix-wizards,net.sources on November 17, 1983.<ref>{{cite web|url=http://securitydigest.org/unix/archive/006|accessdate=2009-11-22|title=The Security Digest Archives}}</ref> The posting seems to be a motivating factor in restricting access to <tt>/dev/kmem</tt> on [[Unix]] systems. The [[user-mode]] program operated by locating and dumping character lists (clists) as they were assembled in the Unix kernel.
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| In the 1970s, spies installed keystroke loggers in the US Embassy and Consulate buildings in Moscow and St Petersburg.<ref>
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| [http://www.qccglobal.com/news/first-keystroke-logger.php "Soviet Spies Bugged World's First Electronic Typewriters"]
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| </ref><ref name="ingersoll">
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| Geoffrey Ingersoll.
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| [http://www.businessinsider.com/russia-turns-to-typewriters-for-secrets-2013-7 "Russia Turns To Typewriters To Protect Against Cyber Espionage"].
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| 2013.
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| </ref>
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| They installed the bugs in [[Selectric]] II and Selectric III electric typewriters.<ref name="gunman">
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| Sharon A. Maneki.
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| [http://www.nsa.gov/about/_files/cryptologic_heritage/center_crypt_history/publications/learning_from_the_enemy_the_gunman_project.pdf "Learning from the Enemy: The GUNMAN Project"].
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| 2012.
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| </ref>
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| Soviet embassies used manual typewriters, rather than electric typewriters, for classified information—apparently because they are immune to such bugs.<ref name=gunman/>
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| As of 2013, Russian special services still use typewriters.<ref name="ingersoll" /><ref>
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| [http://technology.inquirer.net/27149/wanted-20-electric-typewriters-for-russia-to-avoid-leaks "Wanted: 20 electric typewriters for Russia to avoid leaks"]
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| </ref><ref>
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| Anna Arutunyan.
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| [http://themoscownews.com/russia/20130711/191758523/Russian-security-agency-to-buy-typewriters-to-avoid-surveillance.html "Russian security agency to buy typewriters to avoid surveillance"].
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| </ref>
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| == Cracking ==
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| Writing simple software applications for keylogging can be trivial, and like any nefarious computer program, can be distributed as a [[Trojan horse (computing)|trojan horse]] or as part of a [[Computer virus|virus]]. What is not trivial for an attacker, however, is installing a covert keystroke logger without getting caught and downloading data that has been logged without being traced. An attacker that manually connects to a host machine to download logged keystrokes risks being traced. A trojan that sends keylogged data to a fixed e-mail address or [[IP address]] risks exposing the attacker.
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| === Trojan ===
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| [[Young and Yung]] devised several methods for solving this problem and presented them in their 1997 [[Institute of Electrical and Electronics Engineers|IEEE]] Security & Privacy paper<ref>A. Young, M. Yung, "Deniable Password Snatching: On the Possibility of Evasive Electronic Espionage," IEEE Symposium on Security & Privacy, pages 224–235, May 4–7, 1997.</ref> (their paper from 1996 touches on it as well).{{Citation needed|date=August 2009}} They presented a deniable password snatching attack in which the keystroke logging trojan is installed using a virus or worm. An attacker who is caught with the virus or worm can claim to be a victim. The [[cryptotrojan]] asymmetrically encrypts the pilfered login/password pairs using the [[public key]] of the trojan author and covertly broadcasts the resulting [[ciphertext]]. They mentioned that the ciphertext can be [[steganography|steganographically]] encoded and posted to a public bulletin board such as [[Usenet]].{{Citation needed|date=August 2009}}
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| === Use by police ===
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| In 2000, the [[Federal Bureau of Investigation|FBI]] used FlashCrest iSpy to obtain the [[Pretty Good Privacy|PGP]] [[passphrase]] of [[Nicodemo Scarfo, Jr.]], son of mob boss [[Nicodemo Scarfo]].<ref>{{cite web|url=http://www.theregister.co.uk/2000/12/06/mafia_trial_to_test_fbi/|title=Mafia trial to test FBI spying tactics: Keystroke logging used to spy on mob suspect using PGP|date=2000-12-06|accessdate=2009-04-19|publisher=[[The Register]]|author=John Leyden}}</ref>
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| Also in 2000, the FBI lured two suspected Russian cyber criminals to the US in an elaborate ruse, and captured their usernames and passwords with a keylogger that was covertly installed on a machine that they used to access their computers in [[Russia]]. The FBI then used these credentials to hack into the suspects' computers in Russia in order to obtain evidence to prosecute them.<ref>{{cite news|url=http://www.theregister.co.uk/2002/08/16/russians_accuse_fbi_agent/|title=Russians accuse FBI Agent of Hacking|publisher=[[The Register]]|date=2002-08-16|author=John Leyden}}</ref>
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| == Countermeasures ==
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| The effectiveness of countermeasures varies, because keyloggers use a variety of techniques to capture data and the countermeasure needs to be effective against the particular data capture technique. For example, an on-screen keyboard will be effective against hardware keyloggers, transparency will defeat some—but not all—screenloggers and an [[anti-spyware]] application that can only disable hook-based keyloggers will be ineffective against kernel-based keyloggers.
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| Also, keylogger program authors may be able to update the code to adapt to countermeasures that may have proven to be effective against them.
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| === Anti keyloggers ===
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| {{Main|Anti keylogger}}
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| An [[anti keylogger]] is a piece of [[software]] specifically designed to detect keyloggers on a computer, typically comparing all files in the computer against a database of keyloggers looking for similarities which might signal the presence of a hidden keylogger. As anti keyloggers have been designed specifically to detect keyloggers, they have the potential to be more effective than conventional anti virus software; some anti virus software do not consider certain keyloggers a virus, as under some circumstances a keylogger can be considered a legitimate piece of software.{{citation needed|date=December 2011}}
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| === Live CD/USB ===
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| Rebooting the computer using a [[Live CD]] or write-protected [[Live USB]] is a possible countermeasure against software keyloggers if the CD is clean of malware and the operating system contained on it is secured and fully patched so that it cannot be infected as soon as it is started. Booting a different operating system does not impact the use of a hardware or BIOS based keylogger.
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| === Anti-spyware / Anti-virus programs ===
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| Many [[anti-spyware]] applications are able to detect some software based keyloggers and quarantine, disable or cleanse them. However, because many keylogging programs are legitimate pieces of software under some circumstances, anti spyware often neglects to label keylogging programs as spyware or a virus. These applications are able to detect software-based keyloggers based on patterns in [[Subroutine|executable code]], [[heuristics]] and keylogger behaviours (such as the use of [[Hooking|hooks]] and certain [[Application programming interface|API]]s).
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| No software-based anti-spyware application can be 100% effective against all keyloggers.{{Citation needed|date=May 2010}}
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| Also, software-based anti-spyware cannot defeat non-software keyloggers (for example, hardware keyloggers attached to keyboards will always receive keystrokes before any software-based anti-spyware application).
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| However, the particular technique that the anti-spyware application uses will influence its potential effectiveness against software keyloggers. As a general rule, anti-spyware applications with [[Ring (computer security)|higher privileges]] will defeat keyloggers with lower privileges. For example, a hook-based anti-spyware application cannot defeat a kernel-based keylogger (as the keylogger will receive the keystroke messages before the anti-spyware application), but it could potentially defeat hook- and API-based keyloggers.
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| === Network monitors ===
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| [[Network monitoring|Network monitors]] (also known as reverse-firewalls) can be used to alert the user whenever an application attempts to make a network connection. This gives the user the chance to prevent the keylogger from "[[phoning home]]" with his or her typed information.
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| === Automatic form filler programs ===
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| {{Main|Form filler}}
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| Automatic form-filling programs may prevent keylogging by removing the requirement for a user to type personal details and passwords using the keyboard. [[Form filler]]s are primarily designed for [[web browser]]s to fill in checkout pages and log users into their accounts. Once the user's account and [[credit card]] information has been entered into the program, it will be automatically entered into forms without ever using the keyboard or [[Clipboard (software)|clipboard]], thereby reducing the possibility that private data is being recorded. However someone with physical access to the machine may still be able to install software that is able to intercept this information elsewhere in the operating system or while in transit on the network. ([[Transport Layer Security]] (TLS) prevents the interception of data in transit by [[Packet analyzer|network sniffers]] and [[Proxy server|proxy tools]].)
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| === One-time passwords (OTP) ===
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| Using [[one-time password]]s may be keylogger-safe, as each password is invalidated as soon as it's used. This solution may be useful for someone using a public computer. However, an attacker who has remote control over such a computer can simply wait for the victim to enter his/her credentials before performing unauthorised transactions on their behalf while their session is active.
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| === Security tokens ===
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| Use of [[smart card]]s or other [[security token]]s may improve security against [[replay attack]]s in the face of a successful keylogging attack, as accessing protected information would require both the (hardware) security token ''as well as'' the appropriate password/passphrase. Knowing the keystrokes, mouse actions, display, clipboard etc. used on one computer will not subsequently help an attacker gain access to the protected resource. Some security tokens work as a type of hardware-assisted one-time password system, and others implement a cryptographic [[challenge-response authentication]], which can improve security in a manner conceptually similar to one time passwords. [[Card reader|Smartcard readers]] and their associated keypads for [[Personal identification number|PIN]] entry may be vulnerable to keystoke logging through a so-called [[supply chain attack]]<ref>{{cite web|url=http://www.theregister.co.uk/2008/10/10/organized_crime_doctors_chip_and_pin_machines/|author=Austin Modine|title=Organized crime tampers with European card swipe devices|date=2008-10-10|accessdate=2009-04-18|publisher=[[The Register]]}}</ref> where an attacker substitutes the card reader/PIN entry hardware for one which records the user's PIN.
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| === On-screen keyboards ===
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| Most on screen keyboards (such as the onscreen keyboard that comes with [[Windows XP]]) send normal keyboard event messages to the external target program to type text. Every software keylogger can log these typed characters sent from one program to another.<ref>{{cite web|url=http://windowssecrets.com/support-alert/2007/07/19/13-How-to-improve-your-security-when-using-a-public-terminal-(part-3-of-4)|author=Ian Richards|title=How to improve your security when using a public terminal (part 3 of 4)|date=2007-07-19|accessdate=2010-06-15|publisher=Windows Secrets}}</ref>
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| Additionally, keylogging software can take screenshots of what is displayed on the screen (periodically, and/or upon each mouse click), which means that although certainly a useful security measure, an on-screen keyboard will not protect from all keyloggers.
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| === Keystroke interference software ===
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| Keystroke interference software is also available.<ref>{{cite web|url=http://networkintercept.com/keystrokeinterference.html|author=Christopher Ciabarra|title=Anti Keylogger|date=2009-06-10|publisher=Networkintercept.com}}</ref>
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| These programs attempt to trick keyloggers by introducing random keystrokes, although this simply results in the keylogger recording more information than it needs to. An attacker has the task of extracting the keystrokes of interest—the security of this mechanism, specifically how well it stands up to [[cryptanalysis]], is unclear.
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| === Speech recognition ===
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| Similar to on-screen keyboards, [[Speech recognition|speech-to-text conversion]] software can also be used against keyloggers, since there are no typing or mouse movements involved. The weakest point of using voice-recognition software may be how the software sends the recognized text to target software after the recognition took place.
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| === Handwriting recognition and mouse gestures ===
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| Also, many [[Personal digital assistant|PDA]]s and lately [[tablet computer|tablet PC]]s can already convert pen (also called stylus) movements on their [[touchscreen]]s to computer understandable text successfully. [[Mouse gestures]] use this principle by using mouse movements instead of a stylus. Mouse gesture programs convert these strokes to user-definable actions, such as typing text. Similarly, [[graphics tablet]]s and [[light pen]]s can be used to input these gestures, however these are less common everyday.
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| The same potential weakness of speech recognition applies to this technique as well.
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| === Macro expanders/recorders ===
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| With the help of many programs, a seemingly meaningless text can be expanded to a meaningful text and most of the time context-sensitively, e.g. "en.wikipedia.org" can be expanded when a web browser window has the focus. The biggest weakness of this technique is that these programs send their keystrokes directly to the target program. However, this can be overcome by using [[#Non technological methods|the 'alternating' technique described below]], i.e. sending mouse clicks to non-responsive areas of the target program, sending meaningless keys, sending another mouse click to target area (e.g. password field) and switching back-and-forth.
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| === Non-technological methods ===
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| Alternating between typing the login credentials and typing characters somewhere else in the focus window<ref>{{cite web|url=http://cups.cs.cmu.edu/soups/2006/posters/herley-poster_abstract.pdf|format=PDF|title=How To Login From an Internet Cafe Without Worrying About Keyloggers|publisher=[[Microsoft Research]]|author=Cormac Herley and Dinei Florencio|date=2006-02-06|accessdate=2008-09-23}}</ref> can cause a keylogger to record more information than they need to, although this could easily be filtered out by an attacker. Similarly, a user can move their cursor using the mouse during typing, causing the logged keystrokes to be in the wrong order e.g., by typing a password beginning with the last letter and then using the mouse to move the cursor for each subsequent letter. Lastly, someone can also use [[context menu]]s to remove, [[cut, copy, and paste]] parts of the typed text without using the keyboard. An attacker who is able to capture only parts of a password will have a smaller [[key space (cryptography)|key space]] to attack if he chose to execute a [[brute-force attack]].
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| Another very similar technique uses the fact that any selected text portion is replaced by the next key typed. e.g., if the password is "secret", one could type "s", then some dummy keys "asdfsd". Then, these dummies could be selected with the mouse, and the next character from the password "e" is typed, which replaces the dummies "asdfsd".
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| These techniques assume incorrectly that keystroke logging software cannot directly monitor the clipboard, the selected text in a form, or take a screenshot every time a keystroke or mouse click occurs. They may however be effective against some hardware keyloggers.
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| == See also ==
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| * [[Anti keylogger]]
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| * [[Black-bag cryptanalysis]]
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| * [[Computer surveillance]]
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| * [[Digital footprint]]
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| * [[Hardware keylogger]]
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| * [[Reverse connection]]
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| * [[Spyware]]
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| * [[Trojan horse (computing)|Trojan horse]]
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| * [[Virtual keyboard]]
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| == References ==
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| {{Reflist|2}}
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| == External links ==
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| <!--===========================({{NoMoreLinks}})===============================-->
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| * {{Dmoz|Computers/Security/Products_and_Tools/Monitoring/Keyloggers/|Keyloggers}}
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| * [http://www.netadmintools.com/art215.html Keylogging] Hardware and software keylogging methods.
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| * [http://www.keylogger.org/monitoring-software-review/tableview.html Keyloggers Comparison] Up-to-date comparison of most popular commercial keyloggers.
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| * [http://www.securityfocus.com/infocus/1829 Introduction to Spyware Keyloggers]
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| * [http://www.viruslist.com/en/analysis?pubid=204791931 Keyloggers: How they work and how to detect them]
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| * [http://cups.cs.cmu.edu/soups/2006/posters/herley-poster_abstract.pdf How To Login From an Internet Cafe Without Worrying About Keyloggers]
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| {{Malware}}
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| {{DEFAULTSORT:Keystroke Logging}}
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| [[Category:Cryptographic attacks]]
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| [[Category:Spyware]]
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| [[Category:Surveillance]]
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| [[Category:Cybercrime]]
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