ATT&CK coverage › Technique

Remote Services: Distributed Component Object Model T1021.003

Adversaries may use Valid Accounts to interact with remote machines by taking advantage of Distributed Component Object Model (DCOM). The adversary may then perform actions as the logged-on user.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon7Image loaded
Sysmon11FileCreate
Security-Auditing4688A new process has been created.
Security-Auditing5145A network share object was checked to see whether client can be granted desired access.
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).

Authoring guide

Patterns shared across the 16 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 (12 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
Image10ends_with 7, eq 3, match 2, starts_with 1\regsvr32.exe, \mmc.exe, rundll32.exe, \BaaUpdate.exe, \pwsh.exe
ParentImage7ends_with 6, match 1\mmc.exe, svchost.exe, \wmiprvse.exe, \services.exe, \svchost.exe
CommandLine5match 4, eq 1, is_null 1{c08afd90-f2a1-11d1-8455-00a0c91f3880}, C:\\Windows\\System32\\mmc.exe -Embedding, &1, Windows\Temp\, \\\\127.0.0.1\\
EventID4eq 41, 4104, 7
ImageLoaded3ends_with 3, match 1\Music\, \AppData\Roaming\, \Contacts\, \Internet Explorer\iertutil.dll, \WsmSvc.dll
EventLog2eq 2Microsoft-Windows-Sysmon/Operational
ParentCommandLine2eq 1, match 1C:\\Windows\\System32\\svchost.exe -k DcomLaunch, taskeng.exe, svchost.exe -k netsvcs
OriginalFileName2eq 2schdplus.exe, foxprow.exe, winproj.exe, WsmWmiPl.dll, WsmSvc.dll
user1ends_with 1$
RelativeTargetName1ends_with 1\Internet Explorer\iertutil.dll
TargetFilename1ends_with 1\Internet Explorer\iertutil.dll
ScriptBlockText1eq 1"*Document.Application.ShellExecute*", "*Document.ActiveView.ExecuteShellCommand*"

Top indicator values (106 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
EventIDeq123
EventLogeqMicrosoft-Windows-Sysmon/Operational2
ParentImageends_with\mmc.exe23
Imageends_with\wscript.exe264
Imageends_with\cscript.exe264
Imageends_with\regsvr32.exe257
Imageends_with\cmd.exe292
Imageends_with\powershell.exe2143
Imageends_with\mmc.exe26
Imagematchrundll32.exe1
ParentImagematchsvchost.exe1
CommandLinematch{c08afd90-f2a1-11d1-8455-00a0c91f3880}1
CommandLineeqC:\\Windows\\System32\\mmc.exe -Embedding1
ParentCommandLineeqC:\\Windows\\System32\\svchost.exe -k DcomLaunch1
ImageLoadedmatch\Videos\1
ImageLoadedmatch\Music\1
ImageLoadedmatch\Links\1
ImageLoadedmatch\Pictures\12
ImageLoadedmatch:\Perflogs\12
ImageLoadedmatch:\Users\Public\12

Common exclusions (1 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
image_loaded_lowereq"*system32*"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 11 rules

Splunk 2 rules

Kusto Query Language 3 rules