Virus:W32/Sality.AA

The virus attempts to terminate running antivirus programs. It can also download and install additional malware on the system.

Installation

The following file may be dropped on the system:

• [System]\drivers\[random].sys

The file is detected as Virus.Win32.Sality.ab.

It will copy itself to removable drives and shared folders as one of the following :

• [randomname].exe
• [randomname].pif
• [randomname].cmd

An autorun.inf file will be created on the drive so that the malware will be executed when it is connected to a computer. It also modifies %windir%\SYSTEM.INI by adding the following section :

• [MCIDRV_VER] DEVICE=[random alphanumeric string]

Infection

Once on the system, the virus searches the hard disk (starting with C:\) and infects any files with the following extensions:

• .exe
• .scr

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

• [HKCU\Software\Microsoft\Windows\CurrentVersion\run]
• [HLKM\Software\Microsoft\Windows\CurrentVersion\run]

The virus appends itself by creating a new 73728 bytes sized section named "[random characters]data". The section contains Sality.AA's obfuscated code.

Entry Point Obscuration

On infection, the first 327 bytes from the file's entry point are overwritten with deobfuscation code. If the user executes the infected file, Sality.AA restores the original entry point code and launches the program in order to mask its presence.

Registry

When run, Sality.AA creates a mutex to ensure only one instance is running. It then modifies a large range of registry entries. The virus attempts to disable processes and services containing strings related to major antivirus software.

Network Connection

The malware connects to the following website to verify an Internet connection :

• https://www.microsoft.com

The malware may connect to the following sites to download and execute additional malware :

• https://kukutrustnet777.info/[...].gif
• https://kukutrustnet888.info/[...].gif
• https://kukutrustnet987.info/[...].gif
• https://www.musikrajt.sk/[...].gif
• https://macedonia.my1.ru/[...].gif
• https://jrsx.jre.net.cn/[...].gif
• https://www.musikrajt.wz.cz/[...].gif
• https://www.solidarnosc.org.pl/lublin/[...].gif
• https://gotcha.goldeye.info/[...].gif

Downloaded files are encrypted. They are unencrypted by the malware to the %temp% folder and executed.

The following URLs may possibly be used to get further instructions:

• https://89.119.67.154/[...]/
• https://klkjwre77638dfqwieuoi888.[...]/
• https://kukutrustnet777888.[...]/

Process Changes

Creates these mutexes:

• op1mutx9

Registry Modifications

Sets these values:

• HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings GlobalUserOffline = 6684751
• HKLM\Software\Microsoft\Windows\CurrentVersion\policies\system EnableLUA = 6422625 [Vista User Access Control Disabled]
• HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List [malware path] = [malware path]:*:Enabled:ipsec [Windows Firewall Disabled]
• HKCU\Software\user914\1214104697 1919251317 = 3276857
• HKCU\Software\user914\1214104697 -456464662 = 3407926
• HKCU\Software\user914\1214104697 1462786655 = 3604530
• HKCU\Software\user914\1214104697 -912929324 = 3735602
• HKCU\Software\user914\1214104697 1006321993 = 3342390
• HKCU\Software\user914\1214104697 -1369393986 = 0600687474703A2F2F7777772E6D7573696B72616A742E736B2F6D61696E662E 67696600687474703A2F2F6D616365646F6E69612E6D79312E72752F6D61696E682E676966006874 74703A2F2F6A7273782E6A72652E6E65742E636E2F6C6F676F732E67696600687474
• HKCU\Software\user914\1214104697 549857331 = 865E52A75BF33F5D5AA15DAFA722193EDDA8540E6C496C04CF492EF296AFD1AFD EDBC79CEA25E0F6F53B2D9CC0FA963F3A4CC745615E85AFE1E18AEA7E620D11174F3892E84 B5B5DD288784938E304B2D65C454E833D6AF929809110987E5B4B3E4D581071DA4948CB9F84
• HKCU\Software\user914 u1_0 = 655360
• HKCU\Software\user914 u2_0 = 655360
• HKCU\Software\user914 u3_0 = 655360
• HKCU\Software\user914 u4_0 = 655360
• HKLM\Software\Microsoft\Tracing\FWCFG EnableFileTracing = 7471188
• HKLM\Software\Microsoft\Tracing\FWCFG EnableConsoleTracing = 7471188
• HKLM\Software\Microsoft\Tracing\FWCFG FileTracingMask = 7209065
• HKLM\Software\Microsoft\Tracing\FWCFG ConsoleTracingMask = 7209065
• HKLM\Software\Microsoft\Tracing\FWCFG MaxFileSize = 7077993
• HKLM\Software\Microsoft\Tracing\FWCFG FileDirectory = %windir%\tracing
• HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile EnableFirewall = 7471209 [Windows Firewall Disabled]
• HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile DoNotAllowExceptions = 7340133
• HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced Hidden = 4718592
• HKCU\Software\Microsoft\Windows\CurrentVersion\policies\system DisableTaskMgr = 6357076 [Task Manager Disabled]
• HKCU\Software\Microsoft\Windows\CurrentVersion\policies\system DisableRegistryTools = 7929970 [Registry Editor Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center AntiVirusOverride = 6619254
• HKLM\SOFTWARE\Microsoft\Security Center AntiVirusDisableNotify = 5111909 [Alerts for no Antivirus Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center FirewallDisableNotify = 5111909 [Alerts for no Firewall Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center FirewallOverride = 6619254
• HKLM\SOFTWARE\Microsoft\Security Center UpdatesDisableNotify = 5111909 [Alerts for no Windows-Updates Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center UacDisableNotify = 5111909
• HKLM\SOFTWARE\Microsoft\Security Center\Svc AntiVirusOverride = 6619254
• HKLM\SOFTWARE\Microsoft\Security Center\Svc AntiVirusDisableNotify = 5111909 [Alerts for no Antivirus Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center\Svc FirewallDisableNotify = 5111909 [Alerts for no Firewall Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center\Svc FirewallOverride = 6619254
• HKLM\SOFTWARE\Microsoft\Security Center\Svc UpdatesDisableNotify = 5111909 [Alerts for no Windows-Updates Disabled]
• HKLM\SOFTWARE\Microsoft\Security Center\Svc UacDisableNotify = 5111909