Detection rules › Splunk

Outbound Network Connection from Java Using Default Ports

Author
Mauricio Velazco, Lou Stella, Splunk
Source
upstream

The following analytic detects outbound network connections from Java processes to default ports used by LDAP and RMI protocols, which may indicate exploitation of the CVE-2021-44228-Log4j vulnerability. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and network traffic logs. Monitoring this activity is crucial as it can signify an attacker's attempt to perform JNDI lookups and retrieve malicious payloads. If confirmed malicious, this activity could lead to remote code execution and further compromise of the affected server.

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1133 External Remote Services, T1190 Exploit Public-Facing Application
PersistenceT1133 External Remote Services

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon3Network connection

Stages and Predicates

Stage 1: tstats

tstats WHERE Processes.process_name IN ("java.exe", "javaw.exe") BY Processes.action, Processes.dest, Processes.original_file_name, Processes.parent_process, Processes.parent_process_exec, Processes.parent_process_guid, Processes.parent_process_id, Processes.parent_process_name, Processes.parent_process_path, Processes.process, Processes.process_exec, Processes.process_guid, Processes.process_hash, Processes.process_id, Processes.process_integrity_level, Processes.process_name, Processes.process_path, Processes.user, Processes.user_id, Processes.vendor_product

Stage 2: search

search

Stage 3: search

search

Stage 4: search

search

Stage 5: join

join type=inner (...)

Stage 6: table

table _time, connection_to_CNC, dest, dest_port, parent_process, parent_process_name, parent_process_path, process, process_hash, process_name, process_path, user

Stage 7: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
All_Traffic.dest_portin
  • 1099
  • 1389
  • 389
  • 636
Processes.process_namein
  • "java.exe"
  • "javaw.exe"