Modified by: Jaime Benigno Reyes
ALIASES:

Backdoor:Win32/Hesetox.A (Microsoft), Trojan-Spy.Win32.Vskim.b (Kaspersky), Infostealer.Vskim (Symantec)

 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: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This backdoor is also known as BlackPOS.

This backdoor 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 commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE
File Compression: UPX
Memory Resident: Yes
Initial Samples Received Date: 21 Jan 2014
Payload: Steals information, Connects to URLs/IPs

Arrival Details

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

  • %Application Data%\svchost.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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

  • Heistenberg2337

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
PCI Compliant SCard = "%Application Data%\svchost.exe"

Other System Modifications

This backdoor creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Application Data%\svchost.exe = "%Application Data%\svchost.exe:*:Enabled:svchost"

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • download and execute arbitrary files
  • update copy of main malware
  • send gathered data

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • www.{BLOCKED}minalworld.la/api/process.php?xy={random values}

Information Theft

This backdoor gathers the following data:

  • operating system
  • computer name
  • card track data

NOTES:

This backdoor scans the memory of all running processes to retrieve card track data.

It skips to scan the following processes:

  • alg.exe
  • csrss.exe
  • ctfmon.exe
  • explorer.exe
  • lsass.exe
  • mscorsvw.exe
  • services.exe
  • smss.exe
  • spoolsv.exe
  • winlogon.exe
  • wscntfy.exe

This backdoor checks for internet connection. If there is none, it will continuously check for the presence of a removable drive with the name KARTOXA007. If found, it drops the following file:

  • {removable drive letter}:\dmpz.log - contains gathered data

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.554.06
FIRST VSAPI PATTERN DATE: 21 Jan 2014
VSAPI OPR PATTERN File: 10.555.00
VSAPI OPR PATTERN Date: 22 Jan 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • PCI Compliant SCard = "%Application Data%\svchost.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Application Data%\svchost.exe = "%Application Data%\svchost.exe:*:Enabled:svchost"

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_HESETOX.CC. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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