Analysis by: Sammy Chua
ALIASES:

TrojanDropper:O97M/Farheyt (Microsoft); Troj/DocDrp-L (Sophos); W97M.Dropper.AQ (BitDefender);

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Spammed via email

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 210,432 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 27 Jan 2016
Payload: Drops files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\bvhjahs.rtf – detected as W2KM_FAREIT.YYSKE
  • %User Temp%\a2j3hkb.rtf – detected as W2KM_FAREIT.YYSKE

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 drops and executes the following files:

  • %User Temp%\sdf2.exe – detected as TSPY_FAREIT.YYSRU

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.298.07
FIRST VSAPI PATTERN DATE: 27 Jan 2016
VSAPI OPR PATTERN File: 12.299.00
VSAPI OPR PATTERN Date: 27 Jan 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Remove malware/grayware files dropped/downloaded by W2KM_FAREIT.YYSKE. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • TSPY_FAREIT.YYSRU

Step 4

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]

Step 5

Scan your computer with your Trend Micro product to delete files detected as W2KM_FAREIT.YYSKE. 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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