BKDR_FYNLOSKI.XN

August 06, 2014
 ALIASES:

Trojan.ADH.SMH (Symantec); Troj/Malit-EX, Mal/MalitRar-B (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Dropper.Generic_c.XRM (AVG)

 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:

1,496,382 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

18 Jul 2014

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 creates the following folders:

  • %System Root%\Documents and Settings\Wilbert
  • %User Profile%\g6721t6zu

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Dropping Routine

This backdoor drops the following files:

  • __tmp_rar_sfx_access_check_40500
  • dVRhaW.DEP
  • Update.com
  • DHNreYhuuqgJ.CWE
  • YVNUzQM.PBK

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

Search and delete these components

[ Learn More ]
There may be some components 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.
  • __tmp_rar_sfx_access_check_40500
  • dVRhaW.DEP
  • Update.com
  • DHNreYhuuqgJ.CWE
  • YVNUzQM.PBK

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\Documents and Settings\Wilbert
  • %User Profile%\g6721t6zu

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_FYNLOSKI.XN. 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.


Did this description help? Tell us how we did.