New Malware Creates a backdoor to Microsoft Exchange servers

Risk:
high
Damage:
high
Platform(s):
Microsoft® Exchange Server
Advisory ID:
ngCERT-2022-0085
Version:
N/A
CVE:
N/A
Published:
July 15, 2022

Summary


Kaspersky Lab researchers uncovered a new malware dubbed SessionManager, which creates a backdoor to Microsoft Exchange servers. This malware is believed to have been in use, undetected, since March 2021, and is aimed at non-governmental organizations (NGOs), governments, and military establishments in Africa, Europe, Asia, and the Middle East. In a cyber espionage campaign spanning multiple continents, Gelsemium, the group allegedly behind this campaign, aims to gain persistent and covert access to the IT infrastructure of several organizations.

Description & Consequence


The SessionManager backdoor is installed as a malicious module within Internet Information Services (IIS), a Microsoft-developed flexible web server that provides web hosting services for Microsoft solutions. According to Kaspersky, its detection rate is also cause for concern because some of its samples were not detected by some of the more popular "online file scanning services.”

Some of SessionManager’s capabilities are:

  1. Sending and manipulating files on infected systems.
  2. Remotely executing commands.
  3. Connecting to endpoints on compromised system’s LAN.
  4. Controlling network traffic.

A successful exploit could mean any or all of the following:

  1. The organization's emails become compromised.
  2. Installation of other malware to garner further privileges on victim’s information infrastructure.
  3. Remote server administration.

Solution


  1. Check loaded IIS modules on Microsoft Exchange servers regularly.
  2. Monitor data traffic for lateral movements and data exfiltration to the internet.
  3. Adhere strictly to data backup policy.
  4. Ensure all software solutions are patched and up-to-date.

Reference


Revision


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