ATT&CK coverage › Technique

System Binary Proxy Execution: CMSTP T1218.003

Adversaries may abuse CMSTP to proxy execution of malicious code. The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.

Events covered

8 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon3Network connection
Sysmon7Image loaded
Sysmon10ProcessAccess
Sysmon12RegistryEvent (Object create and delete)
Sysmon13RegistryEvent (Value Set)
Sysmon14RegistryEvent (Key and Value Rename)
Security-Auditing4688A new process has been created.

Authoring guide

Patterns shared across the 11 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (13 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
Image5ends_with 3, in 2\cmstp.exe, "*\\windows\\*", "*\\program files*", "*\\wbem\\*"
ImageLoaded5in 3, match 1, ends_with 1, eq 1\PerfLogs\, C:\Temp\, \Users\, "*\\CMLUAUTIL.dll", "*\\CMLUA.dll"
EventID4eq 47
ParentImage2ends_with 2\cmstp.exe, \DllHost.exe
OriginalFileName1eq 1CMSTP.EXE
CommandLine1match 1-s, -au, /ni
CallTrace1match 1cmlua.dll
TargetObject1match 1\cmmgr32.exe
ParentCommandLine1match 1 /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}, /Processid:{BD54C901-076B-434E-B6C7-17C531F4AB41}, /Processid:{E9495B87-D950-4AB5-87A5-FF6D70BF3E90}
IntegrityLevel1eq 1S-1-16-16384, System, High
Initiated1eq 1true
dest_ip1cidr_match 110.0.0.0/8, ::1/128, fe80::/10
process_name1ne 1"colorcpl.exe"

Top indicator values (51 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
EventIDeq7435
Imageends_with\cmstp.exe39
Imagein"*\\program files*"22
Imagein"*\\windows\\*"22
CommandLinematch-au1
CommandLinematch/au1
CommandLinematch/s13
CommandLinematch/ni1
OriginalFileNameeqCMSTP.EXE14
CommandLinematch-s12
CommandLinematch-ni1
CallTracematchcmlua.dll1
ParentImageends_with\cmstp.exe1
TargetObjectmatch\cmmgr32.exe1
ParentImageends_with\DllHost.exe12
IntegrityLeveleqS-1-16-12288116
ParentCommandLinematch /Processid:{3E000D72-A845-4CD9-BD83-80C07C3B881F}1
ParentCommandLinematch /Processid:{E9495B87-D950-4AB5-87A5-FF6D70BF3E90}1
ParentCommandLinematch /Processid:{BD54C901-076B-434E-B6C7-17C531F4AB41}1
ParentCommandLinematch /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}1

Common exclusions (25 distinct)

Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths.

FieldKindValueRules excluding
Imagein"*\\program files*"3
Imagein"*\\windows\\*"3
process_namein"CMMGR32.exe"1
process_namein"CMSTP.exe"1
process_namein"wmiprvse.exe"1
process_namein"unsecapp.exe"1
process_namein"WmiApSrv.exe"1
Imagein"*\\wbem\\*"1
process_namein"*\\AppData\\Local\\slack\\slack.exe"1
process_namein"*:\\Program Files\\Google\\Google Earth Pro\\client\\googleearth.exe"1
process_namein"*:\\Program Files\\Code42\\CrashPlan\\Code42Service.exe"1
process_namein"*:\\Program Files (x86)\\VMware\\VMware Horizon View Client\\vmware-view.exe"1
process_namein"*:\\Program Files (x86)\\Dropbox\\Client\\Dropbox.exe"1
process_namein"*:\\Program Files (x86)\Mozilla Firefox\\firefox.exe"1
process_namein"*:\\Program Files\\Cyberfox\cyberfox.exe"1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 7 rules

Splunk 4 rules