DESCRIPTION NAME:

Unregistered mail server - Email

 CONFIDENCE LEVEL: LOW
 SEVERITY INBOUND:
 SEVERITY OUTBOUND:
Informational
Low
Medium
High

  OVERVIEW

This is Trend Micro detection for packets passing through SMTP network protocols that manifests unusual behavior which can be a potential intrusion. Below are some indicators of unusual behavior:

  • Suspicious activity in administrator or privileged accounts
  • Dubious logins, access, and other network activities that indicate probing or brute force attacks
  • Anomalous spike of requests
  • Network traffic that traverses in unusually used ports
  • Unknown files, applications, and processes in the system
  • Unusual traffic going in and out of the network
  • Unusual message or file structure

  TECHNICAL DETAILS

Protocol: SMTP

Risk Type: MALWARE

Threat Type: Suspicious behavior

Confidence Level: Low

Severity: Informational(Outbound)

DDI Default Rule Status: Enable

Event Class: Suspicious Traffic

Event Sub Class: Email

APT Related: NO

  SOLUTION

Network Content Correlation Pattern Version: 1.12439.00
Network Content Correlation Pattern Release Date: 21 Jan 2016

Immediate Action

  • Update your Trend Micro products and pattern files to the latest version.
  • Scan the host exhibiting this type of network behavior to clean any detected items.

Secondary Action

If scanning fails to detect a malware infection:

  1. If possible, disconnect the host from the network to prevent any further communication or malicious activities the malware may attempt.
  2. Run RootkitBuster to check through hidden files, registry entries, processes, drivers, and hooked system services.
  3. Use the Anti-Threat Toolkit (ATTK) tools to collect undetected malware information.
  4. Identify and clean threats with Rescue Disk, specific to suspected threats that are persistent or difficult-to-clean. Rescue Disk allows you to use a CD, DVD, or USB drive to examine your computer without launching Microsoft Windows.


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