TROJ_INJECT.YYKL

May 23, 2014
 Analysis by: Jimelle Monteser
 ALIASES:

Trojan:Win32/AgentBypass.gen!K (Microsoft); RDN/Generic.dx!d2y (McAfee); Backdoor.Trojan (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Crypt3.MDP (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:
 INFORMATION EXPOSURE:

  • 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:

18,432 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

20 May 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.

Installation

This Trojan stays memory-resident by creating remote threads:

  • %System%\calc.exe
  • %Windows%\explorer.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.806.04

FIRST VSAPI PATTERN DATE:

20 May 2014

VSAPI OPR PATTERN File:

10.807.00

VSAPI OPR PATTERN Date:

21 May 2014

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

Scan your computer with your Trend Micro product and note files detected as TROJ_INJECT.YYKL

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete files detected as TROJ_INJECT.YYKL

[ 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.

Step 5

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