Name:UAC Bypass With Colorui COM Object id:2bcccd20-fc2b-11eb-8d22-acde48001122 version:4 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects a potential UAC bypass using the colorui.dll COM Object. It leverages Sysmon EventCode 7 to identify instances where colorui.dll is loaded by a process other than colorcpl.exe, excluding common system directories. This activity is significant because UAC bypass techniques are often used by malware, such as LockBit ransomware, to gain elevated privileges without user consent. If confirmed malicious, this could allow an attacker to execute code with higher privileges, leading to further system compromise and persistence within the environment. Data_source:
-Sysmon EventID 7
search:`sysmon` EventCode=7 ImageLoaded="*\\colorui.dll" process_name != "colorcpl.exe" NOT(Image IN("*\\windows\\*", "*\\program files*")) | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded process_name dest user_id EventCode Signed ProcessId | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `uac_bypass_with_colorui_com_object_filter`
how_to_implement:To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. known_false_positives:not so common. but 3rd part app may load this dll. References: -https://news.sophos.com/en-us/2020/04/24/lockbit-ransomware-borrows-tricks-to-keep-up-with-revil-and-maze/ drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Ransomware' - 'LockBit Ransomware' asset_type:Endpoint confidence:80 impact:60 message:The following module $ImageLoaded$ was loaded by a non-standard application on endpoint $dest$. mitre_attack_id: - 'T1218' - 'T1218.003' observable: name:'dest' type:'Hostname' - role: - 'Victim' name:'ImageLoaded' type:'Other' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'Image' - 'ImageLoaded' - 'process_name' - 'dest' - 'EventCode' - 'Signed' - 'ProcessId' risk_score:48 security_domain:endpoint
