ALIASES:

Trojan:Win32/Tesch.B (Microsoft), a variant of Win32/Kryptik.CSQB (ESET)

 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: Downloaded from the Internet

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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 108,544 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 Dec 2014
Payload: Connects to URLs/IPs

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.

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • winup.exe

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}bo.com/img/leftcolumn?utm_compain=599aaacb2fe486bea9e523aa151fcc47&utm_source={value}
  • http://{BLOCKED}bo.com/img/rightcolumn?utm_compain=599aaacb2fe486bea9e523aa151fcc47&utm_source={value}

It saves the files it downloads using the following names:

  • {malware path and filename}.bac.exe

    The downloaded file will be executed with a parameter:
    {malware path and filename}.bac.exe 2700

Other Details

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.342.01
FIRST VSAPI PATTERN DATE: 13 Dec 2014
VSAPI OPR PATTERN File: 11.343.00
VSAPI OPR PATTERN Date: 14 Dec 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

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

Identify and terminate files detected as TROJ_TESCH.PAA

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_TESCH.PAA. 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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