Detection rules › Splunk
CDB Execution (Windows Event Log)
CDB is a legitimate Windows component that can be used, and abused, to launch 64-bit shellcode, setup network connections or attaching to any process and executing shell commands. As this is a common component on Windows, it can be leveraged to perform living-off-the-land attacks
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1127 Trusted Developer Utilities Proxy Execution |
| Stealth | T1127 Trusted Developer Utilities Proxy Execution |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '13470.19295'
title: CDB Execution
description: 'CDB is a legitimate Windows component that can be used, and abused,
to launch 64-bit shellcode, setup network connections or attaching to any process
and executing shell commands. As this is a common component on Windows, it can be
leveraged to perform living-off-the-land attacks. -- Threat Actor Association: Metador
-- Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) ("cdb.exe" ("-cf" OR "-cfr" OR ("-premote" ("port"
OR "pipe")) OR ("-pd" "-pn"))) OR ("-cf" OR "-cfr" OR ("-premote" ("port" OR "pipe"))
OR ("-pd" "-pn")) | regex process="(?i)\s+\-(cf|cfr|premote|pd.*-pn|pn.*-pd)\s+"
| table _time, host, user process, process_*, signature_id, parent_* | bin span=1s
| stats values(*) as * by _time, host '
techniques:
- defense-evasion:trusted developer utilities proxy execution
technique_id:
- T1127
data_category:
- Windows event logs
- Process command-line parameters
references:
- https://lolbas-project.github.io/lolbas/OtherMSBinaries/Cdb/
- https://blog.thecybersecuritytutor.com/the-power-of-cdb-debugging-tool/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) ("cdb.exe" ("-cf" OR "-cfr" OR ("-premote" ("port" OR "pipe")) OR ("-pd" "-pn"))) OR ("-cf" OR "-cfr" OR ("-premote" ("port" OR "pipe")) OR ("-pd" "-pn"))
Stage 2: regex
| regex process="(?i)\s+\-(cf|cfr|premote|pd.*-pn|pn.*-pd)\s+"
Stage 3: table
| table _time, host, user process, process_*, signature_id, parent_*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
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.
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4688<" |
| 1 | "cdb.exe" |
| 1 | "-cf" |
| 1 | "-cfr" |
| 1 | "-premote" |
| 1 | "port" |
| 1 | "pipe" |
| 1 | "-pd" |
| 1 | "-pn" |
| 1 | "-cf" |
| 1 | "-cfr" |
| 1 | "-premote" |
| 1 | "port" |
| 1 | "pipe" |
| 1 | "-pd" |
| 1 | "-pn" |