ALIASES:

Downloader-FSH!239AFC70CCD7 (McAfee); Trojan.Cryptodefense (Symantec); Trojan-Dropper.Win32.Injector.ksmg (Kaspersky); Troj/Ransom-AMM (Sophos); Win32.Malware!Drop (Sunbelt); Trojan horse Downloader.Generic14.CTE (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 38,912 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 21 Oct 2014

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\tfosy.exe
  • aeifo.exe

(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.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}233.13/0910t/CWS06D105/0/51-SP2/0
  • http://{BLOCKED}233.13/0910t/CWS06D105/1/0/0
  • http://{BLOCKED}utdirect.com/image/flags/crypt300.rtf
  • http://{BLOCKED}233.13/0910t/CWS06D105/41/5/0
  • {BLOCKED}0.245.114

It deletes itself after execution.

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.
  • %User Temp%\tfosy.exe
  • aeifo.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_CRYPCTB.G. 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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