Analysis by: Henry Alarcon Jr.

ALIASES:

N/A

 PLATFORM:

Linux

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 1,342,085 bytes
File Type: ELF
File Compression: UPX
Memory Resident: Yes
Initial Samples Received Date: 04 Sep 2019
Payload: Connects to URLs/IPs

Arrival Details

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

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Send the content of the following files:
    • /usr/include/olog.h.h

It connects to the following websites to send and receive information:

  • info.{BLOCKED}talk.tk
  • info.{BLOCKED}let.tk

Other Details

This Backdoor does the following:

  • It checks for the presence of the following files:
    • /usr/include/olog.h
    • If the file exists, it will execute the following commands:
      • cat /usr/include/olog.h |sort|uniq > /usr/include/.tmp
      • cat /usr/include/ilog.h |sort|uniq > /usr/include/.tmp
      • then creates the following copies of it into the affected system and restore to its last modified time stamp:
        • /usr/include/olog.h.h
        • /usr/include/ilog.h.h
        • finally deletes the following files:
          • /usr/include/olog.h
          • /usr/include/ilog.h
          • /usr/include/.tmp
    • modify by adding the file:
      • /usr/include/ilog.h

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.344.08
FIRST VSAPI PATTERN DATE: 04 Sep 2019
VSAPI OPR PATTERN File: 15.345.00
VSAPI OPR PATTERN Date: 05 Sep 2019

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Linux.SKIDMAP.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 the following Trend Micro Support pages for more information:


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