DDI RULE 4431
Port-Protocol Mismatches on Non-Standard Port
OVERVIEW
This
is Trend Micro detection for packets passing through various network protocols for connections
whose port does not match standard protocol. This may indicate a malware infection.
Below are some indicators of an infected host:
- Exploit
attempts on hosts inside or outside the network, and denial of service (DoS) attacks on
hosts outside the network, which often result in degraded network performance and
further propagation of the malware.
- Keylogging and stealing of
confidential data.
TECHNICAL DETAILS
Attack Phase: Command and Control Communication
Protocol: TCP/UDP
Risk Type: Others
Threat Type: Suspicious Behavior
Confidence Level: High
Severity: Informational(Inbound)
DDI Default Rule Status: Disabled
Event Class: Suspicious Traffic
Event Sub Class: Port Mis-use
Behavior Indicator: Callback
APT Related: No
SOLUTION
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:
- If possible, disconnect the host from the network to prevent any further communication or malicious activities the malware may attempt.
- Run RootkitBuster to check through hidden files, registry entries, processes, drivers, and hooked system services.
- Use the Anti-Threat Toolkit (ATTK) tools to collect undetected malware information.
- 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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