Analysis by: Rika Joi Gregorio
ALIASES:

Backdoor:Win32/Thoper.E(Microsoft), Win32/Korplug.J trojan(Eset)

 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:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 225,280 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 16 Jul 2013

Arrival Details

This Trojan may be dropped by other malware.

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\SS

HKEY_CLASSES_ROOT\SS\PROXY

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
SS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
SS\PROXY

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}se.{BLOCKED}manage.com/update?id={random}

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.158.02
FIRST VSAPI PATTERN DATE: 16 Jul 2013
VSAPI OPR PATTERN File: 10.159.00
VSAPI OPR PATTERN Date: 17 Jul 2013

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 key

[ 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_CLASSES_ROOT
    • SS

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_GRAFTOR.AT. 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.

NOTES:
Once the key, HKEY_CLASSES_ROOT\SS, has been removed, the registry key in HKEY_LOCAL_MACHINE will also be removed automatically.


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