Modification of Default Startup Folder in the Registry Key 'Common Startup'

Hypothesis and description

Detection of the modification of the registry key Common Startup located in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\ and HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\. When a user logs on, any files located in the Startup Folder are launched. Attackers may modify these folders with other files in order to evade detection set on these default folders. This detection focuses on EventIDs 4688 and 1 for process creation and EventID 4657 for the modification of the Registry Keys.

Platforms: Windows
Domain: Host
Subtypes: Process, Registry
Submitted: 2021-12-06
Contributors: Lucas Heiligenstein

ATT&CK coverage

Technique	Tactics	Coverage
T1547 Boot or Logon Autostart ExecutionT1547.001	Persistence, Privilege Escalation	Medium
T1112 Modify Registry	Stealth (formerly Defense Evasion)	Medium

2 techniques, 3 ATT&CK ids including sub-techniques. Links open MITRE ATT&CK.

Marked techniques are also explained, with detection notes and certification relevance, on our interactive ATT&CK map.

D3FEND techniques MITRE maps to this analytic

D3-PSA Process Spawn Analysis

Data model references

Fields from the CAR data model (object/action/field) the analytic reads.

Pseudocode and implementations

PseudocodeCommon Startup Registry Key ModificationData model: CAR native

This detects modification of the Common Startup registry key value, either via a new process (command line) or direct registry manipulation.

processes = search Process:create
logon_reg_processes = filter processes where (command_line CONTAINS("*reg*") AND command_line CONTAINS("*add*") AND command_line CONTAINS("*/d*") OR (command_line CONTAINS("*Set-ItemProperty*") AND command_line CONTAINS("*-value*")) AND command_line CONTAINS("*Common Startup*"))
reg_keys = search Registry:value_edit
logon_reg_keys = filter reg_keys where value="Common Startup"
output logon_reg_processes, logon_reg_keys

SplunkSplunk Search - Modification of default Startup Folder in the Registry Key "Common Startup"

This is a Splunk representation of the above pseudocode search.

(((EventCode="4688" OR EventCode="1") (CommandLine="*reg*" AND CommandLine="*add*" AND CommandLine="*/d*") OR (CommandLine="*Set-ItemProperty*" AND CommandLine="*-value*") CommandLine="*Common Startup*") OR ((EventCode="4657" ObjectValueName="Common Startup") OR (EventCode="13" TargetObject="*Common Startup")))

ElasticElastic Search - Modification of default Startup Folder in the Registry Key "Common Startup"

This is an ElasticSeearech representation of the above pseudocode search.

((EventLog:"Security" AND (winlog.event_id:"4688" OR winlog.event_id:"1") AND ((process.command_line:*reg* AND process.command_line:*add* AND process.command_line:*\/d*) OR (process.command_line:*Set\-ItemProperty* AND process.command_line:*\-value*)) AND process.command_line:*Common\ Startup*) OR (winlog.event_id:"4657" AND winlog.event_data.ObjectValueName:"Common\ Startup") OR (winlog.event_id:"13" AND winlog.event_data.TargetObject:"*Common Startup"))

LogPointLogPoint Search - Modification of default Startup Folder in the Registry Key "Common Startup"

This is a LogPoint representation of the above pseudocode search.

((EventLog="Security" (event_id="4688" OR event_id="1") ((CommandLine="*reg*" CommandLine="*add*" CommandLine="*/d*") OR (CommandLine="*Set-ItemProperty*" CommandLine="*-value*")) CommandLine="*Common Startup*") OR (event_id="4657" ObjectValueName="Common Startup") OR (event_id="13" TargetObject="*Common Startup"))

Across MITRE's defensive frameworks

Linked through the 2 ATT&CK techniques above.

Counter with D3FEND

Defensive techniques MITRE D3FEND maps to the same ATT&CK techniques.

13 more in the full list

View CAR-2021-12-002 on car.mitre.org