PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via network shares, Downloaded from the Internet

DISTTRACK, also known as Shamoon, is known for infecting the Master Boot Record (MBR) and overwriting files. Accordingly, once these files are overwritten, users cannot open or restore thir access. This malware family of worms propagate via network shares.

  TECHNICAL DETAILS

Memory Resident: Yes
Payload: Overwrites files

Installation

This worm drops the following copies of itself into the affected system:

  • %System%\trksvr.exe
  • \{IP address}\ADMIN$\system32\{random file name}.exe
  • \{IP address}\C$\WINDOWS\system32\{random file name}.exe
  • \{IP address}\D$\WINDOWS\system32\{random file name}.exe
  • \{IP address}\E$\WINDOWS\system32\{random file name}.exe
  • \{command-line parameter}\ADMIN$\system32\{random file name}.exe
  • \{command-line parameter}\C$\WINDOWS\system32\{random file name}.exe
  • \{command-line parameter}\D$\WINDOWS\system32\{random file name}.exe
  • \{command-line parameter}\E$\WINDOWS\system32\{random file name}.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

This worm registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
Type = "10"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
ErrorControl = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
ImagePath = "%System\trksvr.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
DisplayName = "Distributed Link Tracking Server"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
DependOnService = "RpcSs"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
DependOnGroup = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TrkSvr
Description = "Enables the Distributed Link Tracking Client service within the same domain to provide more reliable and efficient maintenance of links within the domain. If this service is disabled, any services that explicitly depend on it will fail to start."

It drops the following files:

  • %System%\{random file name}.exe
  • %System%\netinit.exe
  • {malware path}\f1.inf
  • {malware path}\f2.inf
  • %System%\Drivers\drdisk.sys
  • %Windows%\inf\netf{4 random characters}.pnf

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)