TrojanSpy.Win32.GOOTKIT.AL

This Trojan Spy arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes then deletes itself afterward.

It gathers certain information on the affected computer.

It connects to certain websites to send and receive information.

Arrival Details

This Trojan Spy arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan Spy drops the following files:

• {Malware Path}\{7 Random Numbers}.bat
• {Malware Path}\{Malware File Name}.inf

It adds the following processes:

• %System%\mstsc.exe "{Malware Path}\{Malware File Name}.exe" → injects itself on a legitimate executable to avoid detection
• {Malware Path}\{7 Random Numbers}.bat → used to delete itself
• cmd /c ""{Malware Path}{7 Random Numbers}.bat" "{Malware Path}\{Malware File Name}.exe""
• attrib -r -s -h "{Malware Path}\{Malware File Name}.exe"

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It executes then deletes itself afterward.

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• ServiceEntryPointThread

It injects codes into the following process(es):

• mstsc.exe → injects itself to avoid detection
• svchost.exe → injects the downloaded payload if downloads succeed

Autostart Technique

This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Count = 1

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Path1 = {Malware Path}\{Malware File Name}.inf

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs
Section1 = DefaultInstall

Other System Modifications

This Trojan Spy adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\AppDataLow → if it successfully downloaded its binary payload
binaryImage{Random} = "HEX VALUES"

Propagation

The said .INF file contains the following strings:

[Version]
signature = "$CHICAGO$"
AdvancedINF = 2.5, "You need a new version of advpack.dll"

[DefaultInstall]
RunPreSetupCommands = {Random Characters}:2

[{Random Characters}]
{Malware Path}\{Malware File Name}.exe

Download Routine

This Trojan Spy accesses the following websites to download files:

• {BLOCKED}ailswimschool.com

Information Theft

This Trojan Spy gathers the following information on the affected computer:

• CPU information
• Memory Information (RAM)
• Network Configuration
• UserName
• ComputerName
• Keyboard activity (keylogging)
• ScreenCapture

Other Details

This Trojan Spy adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
IEAK\GroupPolicy\PendingGPOs

It connects to the following website to send and receive information:

• {BLOCKED}spelrk.com
• {BLOCKED}ailswimschool.com
• {BLOCKED}uechallenge.com
• {BLOCKED}u.org
• {BLOCKED}k.org
• {BLOCKED}u.org

It does the following:

• It has the following capabilities:
  • It saves its downloaded payload as an encrypted binary blob in the registry before injecting it into a newly spawned svchost.exe.
  • Monitor web browsing activities (HTTP and HTTPS) via proxy on port 6000
  • Load additional modules to perform other malicious behavior, such as:
  • Keylogging
  • Modify proxy settings
  • Screen Capture
• It has the following anti-analysis techniques:
  • It checks for the following environment variable, if matched it will skip its anti-sandbox and anti-analysis routine:
  • crackmeololo
  • It checks the string "Xeon" at HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcess\0\ProcessorNameString
  • It checks the MAC address of the machine if match with the following hardcoded MAC Address that corresponds the following vendors:
  • F01FAF00 → Dell
  • 00505600 → VMWare
  • 8002700P → PCS System Technology GmbH
  • 000C2900 → VMWare
  • 00056900 → VMWare
  • 0003FF00 → Microsoft
  • 001C4200 → Parallels
  • 00163E00 → XenSource
  • It searches for any of the following loaded module:
  • dbghelp.dll
  • sbiedll.dll
  • It checks if the UserName matches the following:
  • CurrentUser
  • Sandbox
  • It checks if the Computer Name matches the following:
  • SANDBOX
  • 7SILVIA
  • It checks the registry key HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System for the following string value:
  • AMI
  • BOCHS
  • VBOX
  • QEMU
  • SMCI
  • INTEL – 6040000
  • FTNT-1
  • SONI
  • It checks the registry key HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\VideoBiosVersion for the following string value:
  • VirtualBox
  • It checks the registry key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\SystemBiosVersion for the following string value:
  • "55274-640-2673064-23950"
  • "76487-644-3177037-23510"
  • "76487-337-8429955-22614"
  • It sets the following environment variables with these corresponding values:
  • standalonemtm = true
  • vendor_id = exe_scheduler_1235
  • Mainprocessoverride = svchost.exe
  • RandomListenPortBase = 6000