Detection Names :	Virus.Win32.Sality.q, W32/Sality.T
Aliases :	PE_SALITY.AS (Trend Micro)
Category:	Malware
Type:	Virus
Platform:	W32
Date of Discovery:	August 14, 2006

A program that secretly and maliciously integrates itself into program or data files. It spreads by integrating itself into more files each time the host program is run.

Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see Removal Instructions.

Virus:W32/Sality.Q is an appending polymorphic file infector virus that uses an Entry Point Obscuring (EPO) technique.

Unlike other file infectors that modify the entry point of the host file to point to the virus code, Sality.Q replaces 122 bytes from the beginning code of the host file with its decryption routine and hides it in its code.

It stores the original code 1,422 bytes away from the start of the last section.


Execution

When the infected executable file has been run, it will drop the following DLL components:


It will then load the vcmgcd32.dll file, which contains the malicious routine. After successfully installing its components, it will then execute the original host file's code to prevent the user from suspecting infection.


Infection

Sality.Q can infect any of the following extensions by searching for files starting from "C:\":


It also infects files with .EXE extensions that are referenced as data in the following registry keys:



Sality.Q appends itself by creating a new section with a section name of "{random characters}data" and has a size of 20480 Bytes.


Activity

Sality  attempts to delete files and processes related to some antivirus products. It also attempts to delete files that it finds with any of the following extensions:


It will try to delete files with filenames starting with any of the following strings:


It may also kill processes that starts with the following strings:


It checks for an Internet connection by querying:


It then attempts to connect to the following URLs:



Registry

During installation, the worm creates the following mutexes to make sure that only one instance of its .dll component is running in memory:


It also modifies %windir%\SYSTEM.INI by adding a section called MCIDRV_VER with key DEVICE and putting a random value inside it.

Example:


The .DLL component can steal cached passwords and also has key logging capabilities. It is injected in all running processes.