TROJ_RETEFE.ASUAM

October 12, 2017
 Analysis by: Rheniel Rhay Ramos
 ALIASES:

Trojan.JS.Agent.dzu (Kaspersky); Trojan:Win32/Skeeyah.A!bit (Microsoft); Trojan.Retefe (Symantec)

 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

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

369,991 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

22 Sep 2017

Payload:

Drops files

Arrival Details

This Trojan may be dropped by the following malware:

Installation

This Trojan drops the following files:

  • %User Temp%\RarSFX0\__tmp_rar_sfx_access_check_2453396 -> deleted afterwards

(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%\RarSFX0\nU5Ekz6qJ213596.js -> detected as JS_RETEFE.L

It creates the following folders:

  • %User Temp%\RarSFX0

(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.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.680.06

FIRST VSAPI PATTERN DATE:

25 Sep 2017

VSAPI OPR PATTERN File:

13.681.00

VSAPI OPR PATTERN Date:

26 Sep 2017

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

Search and delete this folder

[ 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.  
  • %User Temp%\RarSFX0

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_RETEFE.ASUAM. 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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