Virus:W32/Sality

Classification

Category :

Malware

Type :

Virus

Aliases :

Virus:W32/Sality, Virus.Win32.Sality, Win32.sality, Spyware.Pws.A, Win32.sality.e

Summary

Sality refers to an old, large family of viruses that infect executable files. Over the years, new functionalities have been added to the malware to keep it active and current. Modern Sality variants can, among other things, act as a backdoor and connect infected machines to a botnet.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

The Sality virus family has been circulating in the wild as early as 2003. Over the years, the malware has been developed and improved with the addition of new features, such as rootkit or backdoor functionality, and so on, keeping it an active and relevant threat despite the relative age of the malware.

Modern Sality variants also have the ability to communicate over a peer-to-peer (P2P) network, allowing an attacker to control a botnet of Sality-infected machines. The combined resources of the Sality botnet may also be used by its controller(s) to perform other malicious actions, such as attacking routers.

Infection

Sality viruses typically infect executable files on local, shared and removable drives. In earlier variants, the Sality virus simply added its own malicious code to the end of the infected (or host) file, a technique known as prepending. The viral code that Sality inserts is polymorphic, a form of complex code that is intended to make analysis more difficult.

Earlier Sality variants were regarded as technically sophisticated in that they use an Entry Point Obscuration (EPO) technique to hide their presence on the system. This technique means that the virus inserts a command somewhere in the middle of an infected file's code, so that when the system is reading the file to execute it and comes to the command, it forces the system to 'jump' to the malware's code and execute that instead. This technique was used to make discovery and disinfection of the malicious code harder.

Payload

Once installed on the computer system, Sality viruses usually also execute a malicious payload. The specific actions performed depend on the specific variant in question, but generally Sality viruses will attempt to terminate processes, particularly those related to security programs. The virus may also attempt to open connections to remote sites, download and run additional malicious files, and steal data from the infected machine.

For representative examples of Sality viruses, see the following descriptions: