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.Snojan.ljt
No family descriptionExamples
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915882F7D0C53685DA3232FD6D29AEE1
19FCF28ED6FED23DEE5C1CFFBD21C259
Tactics and Techniques: Mitre*
Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).
On Linux and Mac, users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name (Citation: Sofacy Komplex Trojan) (Citation: Antiquated Mac Malware). Files and folders that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable.
Files on macOS can also be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app (Citation: WireLurker). On Windows, users can mark specific files as hidden by using the attrib.exe binary. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys.
Adversaries can use this to their advantage to hide files and folders anywhere on the system and evading a typical user or system analysis that does not incorporate investigation of hidden files.
Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).
On Linux and Mac, users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name (Citation: Sofacy Komplex Trojan) (Citation: Antiquated Mac Malware). Files and folders that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable.
Files on macOS can also be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app (Citation: WireLurker). On Windows, users can mark specific files as hidden by using the attrib.exe binary. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys.
Adversaries can use this to their advantage to hide files and folders anywhere on the system and evading a typical user or system analysis that does not incorporate investigation of hidden files.
Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
Protocols such as HTTP/S(Citation: CrowdStrike Putter Panda) and WebSocket(Citation: Brazking-Websockets) that carry web traffic may be very common in environments. HTTP/S packets have many fields and headers in which data can be concealed. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
Protocols such as HTTP/S(Citation: CrowdStrike Putter Panda) and WebSocket(Citation: Brazking-Websockets) that carry web traffic may be very common in environments. HTTP/S packets have many fields and headers in which data can be concealed. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
Adversaries may use an existing, legitimate external Web service as a means for relaying data to/from a compromised system. Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.
Use of Web services may also protect back-end C2 infrastructure from discovery through malware binary analysis while also enabling operational resiliency (since this infrastructure may be dynamically changed).
* © 2024 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.