BKDR_FARFLI.FI

 Analysis by: Nikko Tamana

 ALIASES:

W32/Magania.HMHE!tr.pws (Fortinet), Backdoor.Win32.Zegost (Ikarus), Backdoor:Win32/Zegost.Q (Microsoft), a variant of Win32/Farfli.OZ trojan (NOD32), Trojan.Win32.Redosdru.C (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Arrives as a component bundled with malware/grayware packages


This malware connects to malicious URLs in order to send information to remote malicious users.

This backdoor arrives as a component bundled with malware/grayware packages.

It executes commands from a remote malicious user, effectively compromising the affected system.

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size:

85,504 bytes

File Type:

DLL

Initial Samples Received Date:

22 Nov 2012

Payload:

Compromises system security, Connects to URLs/IPs, Steals information

Arrival Details

This backdoor arrives as a component bundled with malware/grayware packages.

Installation

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

  • kr.chongzi.kr:53:

Backdoor Routine

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

  • Send stolen information
  • Enumerate running processes
  • Logs the user off
  • Manipulate registry
  • Download file from the internet
  • Get drive information
  • Execute cmd shell commands

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

  • kr.{BLOCKED}i.kr

Stolen Information

This backdoor saves the stolen information in the following file:

  • %System%\update08932.log

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Other Details

This backdoor requires its main component to successfully perform its intended routine.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.542.02

FIRST VSAPI PATTERN DATE:

22 Nov 2012

VSAPI OPR PATTERN File:

9.543.00

VSAPI OPR PATTERN Date:

23 Nov 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Scan your computer with your Trend Micro product and note files detected as BKDR_FARFLI.FI

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the file detected as BKDR_FARFLI.FI

*Note: Some component files may be hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.

To manually delete a malware/grayware file from the affected system:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

Step 5

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %System%\update08932.log

Step 6

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