PH_Rule_TH_Linux_39
Enabled
Detects suspicious VSFTPD error messages that indicate a fatal or suspicious error that could be caused by exploit attempts
7
Security
Execution
Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.
https://attack.mitre.org/tactics/TA0002No Technique Specified
Server
Linux via Syslog
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Download
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType CONTAIN "Generic_Unix_" AND
(rawEventMsg CONTAIN "Connection refused: too many sessions for this address" OR
rawEventMsg CONTAIN "Connection refused: tcp_wrappers denial" OR
rawEventMsg CONTAIN "Bad HTTP verb" OR
rawEventMsg CONTAIN "port and pasv both active" OR
rawEventMsg CONTAIN "pasv and port both active" OR
rawEventMsg CONTAIN "Transfer done (but failed to open directory)" OR
rawEventMsg CONTAIN "Could not set file modification time" OR
rawEventMsg CONTAIN "bug: pid active in ptrace_sandbox_free" OR
rawEventMsg CONTAIN "PTRACE_SETOPTIONS failure" OR
rawEventMsg CONTAIN "weird status:" OR
rawEventMsg CONTAIN "couldn't handle sandbox event" OR
rawEventMsg CONTAIN "syscall not permitted" OR
rawEventMsg CONTAIN "syscall validate failed" OR
rawEventMsg CONTAIN "Input line too long" OR
rawEventMsg CONTAIN "poor buffer accounting in str_netfd_alloc" OR
rawEventMsg CONTAIN "vsf_sysutil_read_loop" OR
rawEventMsg REGEXP ".*syscall .* out of bounds.*") AND phEventCategory = 0
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
reptDevName
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
hostName = Download.reptDevName