BKDR_KELIHOS.WPD

March 08, 2013
 Analysis by: Nikko Tamana
 ALIASES:

Mal/FakeAV-OY (Sophos), Trojan-PWS.Win32.Tepfer (Ikarus), Trojan-PSW.Win32.Tepfer.gdwj (Kaspersky), Backdoor:Win32/Kelihos.F (Microsoft),

 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: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

786,944 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Mar 2013

Payload:

Connects to URLs/IPs, Sends messages, Steals information

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.

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
SonyAgent = "{Malware Path and File Name}"

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.178.9
  • http://{BLOCKED}.{BLOCKED}.43.24
  • http://{BLOCKED}.{BLOCKED}.188.94

NOTES:

This backdoor modifies its file attributes into read-only and hidden after execution.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.772.04

FIRST VSAPI PATTERN DATE:

07 Mar 2013

VSAPI OPR PATTERN File:

9.773.00

VSAPI OPR PATTERN Date:

08 Mar 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

Scan your computer with your Trend Micro product and note files detected as BKDR_KELIHOS.WPD

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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
    • SonyAgent = "{Malware Path and File Name}"

Step 5

Search and delete the file detected as BKDR_KELIHOS.WPD

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 6

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