Keyloggers and Spywares

Go back to Tutorial

Keylogger

Keystroke logging, often referred to as keylogging or keyboard capturing, is the action of recording (or logging) the keys struck on a keyboard, typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored.

It has the capability to record every keystroke you make to a log file, usually encrypted. A keylogger recorder can record instant messages, e-mail, and any information you type at any time using your keyboard. The log file created by the keylogger can then be sent to a specified receiver. Some keylogger programs will also record any e-mail addresses you use and Web site URLs you visit.

Legitimate programs may have a keylogging function which can be used to call certain program functions using “hotkeys,” or to toggle between keyboard layouts (e.g. Keyboard Ninja). There is a lot of legitimate software which is designed to allow administrators to track what employees do throughout the day, or to allow users to track the activity of third parties on their computers. However, the ethical boundary between justified monitoring and espionage is a fine line. Legitimate software is often used deliberately to steal confidential user information such as passwords.

Most modern keyloggers are considered to be legitimate software or hardware and are sold on the open market. Developers and vendors offer a long list of cases in which it would be legal and appropriate to use keyloggers, including:

• Parental control: parents can track what their children do on the Internet, and can opt to be notified if there are any attempts to access websites containing adult or otherwise inappropriate content;
• Jealous spouses or partners can use a keylogger to track the actions of their better half on the Internet if they suspect them of “virtual cheating”;
• Company security: tracking the use of computers for non-work-related purposes, or the use of workstations after hours;
• Company security: using keyloggers to track the input of key words and phrases associated with commercial information which could damage the company (materially or otherwise) if disclosed;
• Other security (e.g. law enforcement): using keylogger records to analyze and track incidents linked to the use of personal computers;
• Other reasons.

Threat

As such programs are extensively used by cyber criminals, detecting them is a priority for antivirus companies. Unlike other types of malicious program, keyloggers present no threat to the system itself. Nevertheless, they can pose a serious threat to users, as they can be used to intercept passwords and other confidential information entered via the keyboard. As a result, cyber criminals can get PIN codes and account numbers for e-payment systems, passwords to online gaming accounts, email addresses, user names, email passwords etc.

Once a cyber criminal has got hold of confidential user data, s/he can easily transfer money from the user’s account or access the user’s online gaming account. Unfortunately access to confidential data can sometimes have consequences which are far more serious than an individual’s loss of a few dollars. Keyloggers can be used as tools in both industrial and political espionage, accessing data which may include proprietary commercial information and classified government material which could compromise the security of commercial and state-owned organizations (for example, by stealing private encryption keys).

Keyloggers, phishing and social engineering are currently the main methods being used in cyber fraud. Users who are aware of security issues can easily protect themselves against phishing by ignoring phishing emails and by not entering any personal information on suspicious websites. It is more difficult, however, for users to combat keyloggers; the only possible method is to use an appropriate security solution, as it’s usually impossible for a user to tell that a keylogger has been installed on his/ her machine.

In recent years, we have seen a considerable increase in the number of different kinds of malicious programs which have keylogging functionality. No Internet user is immune to cyber criminals, no matter where in the world s/he is located and no matter what organization s/he works for.

Attacks

One of the most publicized keylogging incidents recently was the theft of over $1million from client accounts at the major Scandinavian bank Nordea. In August 2006 Nordea clients started to receive emails, allegedly from the bank, suggesting that they install an antispam product, which was supposedly attached to the message. When a user opened the file and downloaded it to his/ her computer, the machine would be infected with a well known Trojan called Haxdoor. This would be activated when the victim registered at Nordea’s online service, and the Trojan would display an error notification with a request to re-enter the registration information. The keylogger incorporated in the Trojan would record data entered by the bank’s clients, and later send this data to the cyber criminals’ server. This was how cyber criminals were able to access client accounts, and transfer money from them. According to Haxdoor’s author, the Trojan has also been used in attacks against Australian banks and many others.

On January 24, 2004 the notorious Mydoom worm caused a major epidemic. MyDoom broke the record previously set by Sobig, provoking the largest epidemic in Internet history to date. The worm used social engineering methods and organized a DoS attack on www.sco.com; the site was either unreachable or unstable for several months as a consequence. The worm left a Trojan on infected computers which was subsequently used to infect the victim machines with new modifications of the worm. The fact that MyDoom had a keylogging function to harvest credit card numbers was not widely publicized in the media.

In early 2005 the London police prevented a serious attempt to steal banking data. After attacking a banking system, the cyber criminals had planned to steal $423 million from Sumitomo Mitsui’s London-based offices. The main component of the Trojan used, which was created by the 32-year-old Yeron Bolondi, was a keylogger that allowed the criminals to track all the keystrokes entered when victims used the bank’s client interface.

There are many more examples of cyber criminals using keyloggers – most financial cybercrime is committed using keyloggers, since these programs are the most comprehensive and reliable tool for tracking electronic information.

Structure

The main idea behind keyloggers is to get in between any two links in the chain of events between when a key is pressed and when information about that keystroke is displayed on the monitor. This can be achieved using video surveillance, a hardware bug in the keyboard, wiring or the computer itself, intercepting input/ output, substituting the keyboard driver, the filter driver in the keyboard stack, intercepting kernel functions by any means possible (substituting addresses in system tables, splicing function code, etc.), intercepting DLL functions in user mode, and, finally, requesting information from the keyboard using standard documented methods.

Experience shows that the more complex the approach, the less likely it is to be used in common Trojan programs and the more likely it is to be used in specially designed Trojan programs which are designed to steal financial data from a specific company.

Keyloggers can be divided into two categories: keylogging devices and keylogging software. Keyloggers which fall into the first category are usually small devices that can be fixed to the keyboard, or placed within a cable or the computer itself. The keylogging software category is made up of dedicated programs designed to track and log keystrokes.

The most common methods used to construct keylogging software are as follows:

• a system hook which intercepts notification that a key has been pressed (installed using WinAPI SetWindowsHook for messages sent by the window procedure. It is most often written in C);
• a cyclical information keyboard request from the keyboard (using WinAPI Get(Async)KeyState or GetKeyboardState – most often written in Visual Basic, sometimes in Borland Delphi);
• using a filter driver (requires specialized knowledge and is written in C).

Hardware Keyloggers

Some keyloggers can be implemented entirely as hardware devices. A typical desktop computer has a keyboard that connects to the back of the computer using a USB cable. If someone were to sneak in, unplug the keyboard’s USB cable, then attach a specialized USB device between the computer’s USB port and the keyboard’s USB connector, the device could function as a keylogger. Sitting in the middle, it could intercept keyboard signals from the keyboard, store them on the device, and then pass the keystrokes to the computer so everything would appear to be working normally. Security software on the computer wouldn’t be able to detect this keylogger, as it runs entirely in hardware. If the computer were hidden under a desk, no one would notice the device.

The person could then come back a few days later to grab the device and sneak off with it, leaving no trace of keylogging software or suspicious network activity.

Stealth

Recently, keyloggers that disguise their files to keep them from being found manually or by an antivirus program have become more numerous. These stealth techniques are called rootkit technologies. There are two main rootkit technologies used by keyloggers:

• masking in user mode;
• masking in kernel mode.

Spread

Keyloggers spread in much the same way that other malicious programs spread. Excluding cases where keyloggers are purchased and installed by a jealous spouse or partner, and the use of keyloggers by security services, keyloggers are mostly spread using the following methods):

• a keylogger can be installed when a user opens a file attached to an email;
• a keylogger can be installed when a file is launched from an open-access directory on a P2P network;
• a keylogger can be installed via a web page script which exploits a browser vulnerability. The program will automatically be launched when a user visits a infected site;
• a keylogger can be installed by another malicious program already present on the victim machine, if the program is capable of downloading and installing other malware to the system.

Protection

Most antivirus companies have already added known keyloggers to their databases, making protecting against keyloggers no different from protecting against other types of malicious program: install an antivirus product and keep its database up to date. However, since most antivirus products classify keyloggers as potentially malicious, or potentially undesirable programs, users should ensure that their antivirus product will, with default settings, detect this type of malware. If not, then the product should be configured accordingly, to ensure protection against most common keyloggers.

Since the chief purpose of keyloggers is to get confidential data (bank card numbers, passwords, etc.), the most logical ways to protect against unknown keyloggers are as follows:

• using one-time passwords or two-step authentication,
• using a system with proactive protection designed to detect keylogging software,
• using a virtual keyboard.

Spyware

Spyware is software that aims to gather information about a person or organization without their knowledge and that may send such information to another entity without the consumer’s consent, or that asserts control over a computer without the consumer’s knowledge.

“Spyware” is mostly classified into four types: system monitors, trojans, adware, and tracking cookies. Spyware is mostly used for the purposes of tracking and storing Internet users’ movements on the Web and serving up pop-up ads to Internet users.

Whenever spyware is used for malicious purposes, its presence is typically hidden from the user and can be difficult to detect.

Installation

Spyware does not necessarily spread in the same way as a virus or worm because infected systems generally do not attempt to transmit or copy the software to other computers. Instead, spyware installs itself on a system by deceiving the user or by exploiting software vulnerabilities.

Most spyware is installed without users’ knowledge, or by using deceptive tactics. Spyware may try to deceive users by bundling itself with desirable software. Other common tactics are using a Trojan horse. Some spyware authors infect a system through security holes in the Web browser or in other software. When the user navigates to a Web page controlled by the spyware author, the page contains code which attacks the browser and forces the download and installation of spyware.

Examples

These common spyware programs illustrate the diversity of behaviors found in these attacks. Note that as with computer viruses, researchers give names to spyware programs which may not be used by their creators. Programs may be grouped into “families” based not on shared program code, but on common behaviors, or by “following the money” of apparent financial or business connections. For instance, a number of the spyware programs distributed by Claria are collectively known as “Gator”. Likewise, programs that are frequently installed together may be described as parts of the same spyware package, even if they function separately.

• CoolWebSearch, a group of programs, takes advantage of Internet Explorer vulnerabilities. The package directs traffic to advertisements on Web sites including coolwebsearch.com. It displays pop-up ads, rewrites search engine results, and alters the infected computer’s hosts file to direct DNS lookups to these sites.
• Internet Optimizer, also known as DyFuCa, redirects Internet Explorer error pages to advertising. When users follow a broken link or enter an erroneous URL, they see a page of advertisements. However, because password-protected Web sites (HTTP Basic authentication) use the same mechanism as HTTP errors, Internet Optimizer makes it impossible for the user to access password-protected sites.

Behavior

A spyware program is rarely alone on a computer: an affected machine usually has multiple infections. Users frequently notice unwanted behavior and degradation of system performance. A spyware infestation can create significant unwanted CPU activity, disk usage, and network traffic. Stability issues, such as applications freezing, failure to boot, and system-wide crashes are also common. Spyware, which interferes with networking software, commonly causes difficulty connecting to the Internet.

In some infections, the spyware is not even evident. Users assume in those situations that the performance issues relate to faulty hardware, Windows installation problems, or another infection. Some owners of badly infected systems resort to contacting technical support experts, or even buying a new computer because the existing system “has become too slow”. Badly infected systems may require a clean reinstallation of all their software in order to return to full functionality.

Moreover, some types of spyware disable software firewalls and anti-virus software, and/or reduce browser security settings, which further open the system to further opportunistic infections. Some spyware disables or even removes competing spyware programs, on the grounds that more spyware-related annoyances make it even more likely that users will take action to remove the programs.

Prevention

As the spyware threat has worsened, a number of techniques have emerged to counteract it. These include programs designed to remove or block spyware, as well as various user practices which reduce the chance of getting spyware on a system.

When a large number of pieces of spyware have infected a Windows computer, the only remedy may involve backing up user data, and fully reinstalling the operating system. For instance, some spyware cannot be completely removed by Symantec, Microsoft, PC Tools.

Go back to Tutorial