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: 25,600 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Apr 2016

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.

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\WINDOW~1.BAT

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\WindowsUpdate.bat

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.199.175

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.8

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 this file

[ Learn More ]
There may be some files 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.
  • %System Root%\WindowsUpdate.bat

Step 3

Scan your computer with your Trend Micro product to delete files detected as Ransom_CRYPCTB.BYX. 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.

Step 4

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\WINDOW~1.BAT


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