ATT&CK coverage › Technique

System Binary Proxy Execution: Mshta T1218.005

Adversaries may abuse mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon8CreateRemoteThread
Sysmon11FileCreate
Sysmon13RegistryEvent (Value Set)
Security-Auditing4688A new process has been created.

Authoring guide

Patterns shared across the 10 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 (11 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
Image8ends_with 7, eq 1\mshta.exe, \csc.exe, \excel.exe, \winword.exe, \System32\mshta.exe
OriginalFileName6eq 6MSHTA.EXE, csc.exe, mshta.exe, REGSVR32.EXE, PowerShell.EXE
ParentImage3ends_with 3, starts_with 1, eq 1\excel.exe, \onenote.exe, C:\Windows\System32\sdiagnhost.exe, \svchost.exe, \mshta.exe
CommandLine3match 3.gz, .gif, .tmp, https://, http://
TargetFilename2in 2"*\\Windows\\tracing\\*", "*\\Windows\\Temp\\*", "*\\Windows\\System32\\Com\\dmp\\*", "*\\Windows\\System32\\LogFiles\\WMI\\*", "*\\Windows\\System32\\Tasks\\*"
ParentCommandLine1match 1, regex_match 1FromBase64String, \Contacts\, :\Windows\Temp\
TargetImage1match 1\SysWOW64\
StartModule1is_null 1
Details1in 1, eq 1"*mshta*", "*vbscript:*", "*javascript:*"
EventID1eq 111
file_name1eq 1*.txt

Top indicator values (130 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
Imageends_with\mshta.exe457
ParentImageends_with\mshta.exe210
OriginalFileNameeqMSHTA.EXE27
TargetFilenamein"*\\Windows\\System32\\spool\\drivers\\color\\*"22
TargetFilenamein"*\\Windows\\System32\\Microsoft\\Crypto\\RSA\\MachineKeys\\*"22
TargetFilenamein"*\\Windows\\Temp\\*"23
TargetFilenamein"*\\Windows\\Registration\\CRMLog\\*"22
TargetFilenamein"*\\Windows\\PLA\\Templates\\*"22
TargetFilenamein"*\\Windows\\PLA\\Reports\\*"22
TargetFilenamein"*\\Windows\\SysWOW64\\Tasks\\*"22
TargetFilenamein"*\\Windows\\Tasks\\*"22
TargetFilenamein"*\\Windows\\System32\\spool\\PRINTERS\\*"22
TargetFilenamein"*\\Windows\\PLA\\Rules\\*"22
TargetFilenamein"*\\Windows\\System32\\Tasks\\*"22
TargetFilenamein"*\\Windows\\tracing\\*"22
TargetFilenamein"*\\Windows\\System32\\LogFiles\\WMI\\*"22
TargetFilenamein"*\\Windows\\System32\\spool\\SERVERS\\*"22
TargetFilenamein"*\\Windows\\System32\\Com\\dmp\\*"22
TargetFilenamein"*\\Windows\\SysWOW64\\Com\\dmp\\*"22
ParentImagestarts_withC:\Program Files\12

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 3 rules