Class: Adware
Adware covers programs designed to display advertisements (usually in the form of banners), redirect search requests to advertising websites, and collect marketing-type data about the user (e.g. which types of websites s/he visits) in order to display customized advertising on the computer. Other than displaying advertisements and collecting data, these types of program generally do not make their presence in the system known: there will be no signs of the program in the system tray, and no indication in the program menu that files have been installed. Often, Adware programs do not have any uninstall procedures and use technologies which border on virus technology to help the program stealthily penetrate the computer and run unnoticed. Penetration There are two main ways in which Adware gets onto a user’s computer: it is built-in to some freeware and shareware programs unauthorized installation to a user’s computer as a result of a visit to an infected website. Most freeware and shareware programs stop displaying advertisements once they have been purchased and/or registered. But these programs often use built-in third-party Adware utilities, and in some cases, these utilities remain installed on the user’s computer even once the programs have been registered. Furthermore, removing the Adware component, which is still being used by a program to display advertisements, could cause the program to malfunction. The main purpose of Adware spread via the first method is to extract a type of payment for the software by showing advertisements to the user (the parties who make the advertisements pay the advertising agency, and the advertising agency pays the Adware developer). Adware also helps cut expenses for software developers (revenue from Adware encourages them to write new programs and improve existing ones), and it helps cut costs for users, too. Hacker technologies are often used when advertising components are installed on a user’s computer following a visit to an infected website. For instance, the computer can be penetrated via a browser vulnerability and Trojans designed to stealthily install (Trojan-Downloader or Trojan-Dropper) can be used. Adware programs that work in this way are often called Browser Hijackers. Displaying advertisements There are two main ways in which advertising is shown to the user: by downloading advertising text and images to a computer from web or FTP servers owned by the advertiser redirecting Internet browser search requests to advertising websites. In some cases, redirect requests takes place only if the user’s requested web page is not available i.e. if is an error in the URL. Collecting data In addition to displaying advertisements, many advertising systems also collect data about the computer and the user, such as: the computer’s IP address the operating system and browser version a list of the most frequently visited sites search queries other data that may be used to conduct subsequent advertising campaigns. Note: it is important not to confuse Adware that collects data with Trojan spyware programs. The difference is that Adware collects data with the user’s consent. If Adware does not notify the user that it is gathering information, then it is classified as a malicious program (Malware), specifically covered by the Trojan-Spy behaviour.Read more
Platform: Win32
Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.Family: AdWare.Win32.InstallMonster
No family descriptionExamples
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Tactics and Techniques: Mitre*
TA0002
Execution
The adversary is trying to run malicious code.
Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.
Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.
T1204.002
User Execution: Malicious File
An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from Spearphishing Attachment. Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, and .cpl.
Adversaries may employ various forms of Masquerading and Obfuscated Files or Information to increase the likelihood that a user will open and successfully execute a malicious file. These methods may include using a familiar naming convention and/or password protecting the file and supplying instructions to a user on how to open it.(Citation: Password Protected Word Docs)
While Malicious File frequently occurs shortly after Initial Access it may occur at other phases of an intrusion, such as when an adversary places a file in a shared directory or on a user's desktop hoping that a user will click on it. This activity may also be seen shortly after Internal Spearphishing.
Adversaries may employ various forms of Masquerading and Obfuscated Files or Information to increase the likelihood that a user will open and successfully execute a malicious file. These methods may include using a familiar naming convention and/or password protecting the file and supplying instructions to a user on how to open it.(Citation: Password Protected Word Docs)
While Malicious File frequently occurs shortly after Initial Access it may occur at other phases of an intrusion, such as when an adversary places a file in a shared directory or on a user's desktop hoping that a user will click on it. This activity may also be seen shortly after Internal Spearphishing.
TA0003
Persistence
The adversary is trying to maintain their foothold.
Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.
Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.
T1546.002
Event Triggered Execution: Screensaver
Adversaries may establish persistence by executing malicious content triggered by user inactivity. Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension.(Citation: Wikipedia Screensaver) The Windows screensaver application scrnsave.scr is located in
The following screensaver settings are stored in the Registry (
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Adversaries can use screensaver settings to maintain persistence by setting the screensaver to run malware after a certain timeframe of user inactivity.(Citation: ESET Gazer Aug 2017)
C:\Windows\System32\, and C:\Windows\sysWOW64\ on 64-bit Windows systems, along with screensavers included with base Windows installations.The following screensaver settings are stored in the Registry (
HKCU\Control Panel\Desktop\) and could be manipulated to achieve persistence:*
SCRNSAVE.exe - set to malicious PE path*
ScreenSaveActive - set to '1' to enable the screensaver*
ScreenSaverIsSecure - set to '0' to not require a password to unlock*
ScreenSaveTimeout - sets user inactivity timeout before screensaver is executedAdversaries can use screensaver settings to maintain persistence by setting the screensaver to run malware after a certain timeframe of user inactivity.(Citation: ESET Gazer Aug 2017)
TA0004
Privilege Escalation
The adversary is trying to gain higher-level permissions.
Privilege Escalation consists of techniques that adversaries use to gain higher-level permissions on a system or network. Adversaries can often enter and explore a network with unprivileged access but require elevated permissions to follow through on their objectives. Common approaches are to take advantage of system weaknesses, misconfigurations, and vulnerabilities. Examples of elevated access include:
* SYSTEM/root level
* local administrator
* user account with admin-like access
* user accounts with access to specific system or perform specific function
These techniques often overlap with Persistence techniques, as OS features that let an adversary persist can execute in an elevated context.
Privilege Escalation consists of techniques that adversaries use to gain higher-level permissions on a system or network. Adversaries can often enter and explore a network with unprivileged access but require elevated permissions to follow through on their objectives. Common approaches are to take advantage of system weaknesses, misconfigurations, and vulnerabilities. Examples of elevated access include:
* SYSTEM/root level
* local administrator
* user account with admin-like access
* user accounts with access to specific system or perform specific function
These techniques often overlap with Persistence techniques, as OS features that let an adversary persist can execute in an elevated context.
T1546.002
Event Triggered Execution: Screensaver
Adversaries may establish persistence by executing malicious content triggered by user inactivity. Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension.(Citation: Wikipedia Screensaver) The Windows screensaver application scrnsave.scr is located in
The following screensaver settings are stored in the Registry (
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Adversaries can use screensaver settings to maintain persistence by setting the screensaver to run malware after a certain timeframe of user inactivity.(Citation: ESET Gazer Aug 2017)
C:\Windows\System32\, and C:\Windows\sysWOW64\ on 64-bit Windows systems, along with screensavers included with base Windows installations.The following screensaver settings are stored in the Registry (
HKCU\Control Panel\Desktop\) and could be manipulated to achieve persistence:*
SCRNSAVE.exe - set to malicious PE path*
ScreenSaveActive - set to '1' to enable the screensaver*
ScreenSaverIsSecure - set to '0' to not require a password to unlock*
ScreenSaveTimeout - sets user inactivity timeout before screensaver is executedAdversaries can use screensaver settings to maintain persistence by setting the screensaver to run malware after a certain timeframe of user inactivity.(Citation: ESET Gazer Aug 2017)
* © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.