Analysis by: Homer Pacag
 PLATFORM:

Linux

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • 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.

  TECHNICAL DETAILS

File Size: 2,182 bytes
File Type: PY
Memory Resident: No
Initial Samples Received Date: 24 Jun 2016
Payload: Encrypts files

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 drops the following files:

  • /root/howto.txt - ransom note

NOTES:

This ransomware targets mail message files of Zimbra mail server. It encrypts files in the opt/zimbra/store subfolders and appends .CRYPTO as the new file extension of the encrypted files.

Information such as private and public keys used for encryption are sent via email by accessing the mail server address {BLOCKED}.{BLOCKED}.5.20 to email address {BLOCKED}en@priest.com.

Below is the message contained in howto.txt:

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.610.04
FIRST VSAPI PATTERN DATE: 24 Jun 2016
VSAPI OPR PATTERN File: 12.611.00
VSAPI OPR PATTERN Date: 24 Jun 2016

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

Scan your computer with your Trend Micro product to delete files detected as RANSOM_ZIRBAM.A. 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 encrypted files from backup.


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