Masquerading: Masquerade Task or Service T1036.004

Tactic: Stealth

Adversaries may attempt to manipulate the name of a task or service to make it appear legitimate or benign. Tasks/services executed by the Task Scheduler or systemd will typically be given a name and/or description. Windows services will have a service name as well as a display name. Many benign tasks and services exist that have commonly associated names. Adversaries may give tasks or services names that are similar or identical to those of legitimate ones.

Events covered

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

Authoring guide

Patterns shared across the 17 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names 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 (19 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
process_name9regex_match 4, starts_with 3, match 2kworker, (?i)\x5csystem32\x5c(lsass|services)\.exe, (?i)\x5csystem32\x5cspoolsv\.exe, (?i)^(svchost\.exe|rundll32\.exe|services\.exe|powershell..., kthread
EventID8eq 81, 4688
parent_process_name6is_not_null 4, regex_match 2(?i)lsass\.exe
Type4eq 4
CommandLine3contains 3, match 1 -exec bypass -enc jgag, /create , audiodg, conhost, /tn win32times /f
EventType3in 2, eq 1ProcessRollup2, connection_accepted, connection_attempted, exec, exec_event
ParentImage3is_not_null 2, in 1/home/*, /tmp/*, /var/log/*
host.os.type3eq 3
Image2ends_with 1, is_not_null 1\schtasks.exe
blocklist_label2eq 21
problemchild.prediction2eq 21
problemchild.prediction_probability2gt 1, le 10.98
CallerProcessName1ends_with 1\checkadmin.exe
OriginalFileName1eq 1schtasks.exe
ParentCommandLine1contains 1[kworker/

Top indicator values (59 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. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
EventIDeq
1
4237
EventIDeq
4688
4313
process_namestarts_with
kworker
34
blocklist_labeleq
1
22
parent_process_nameregex_match
(?i)lsass\.exe
22
problemchild.predictioneq
1
22
process_namematch
(?i)^(svchost\.exe|rundll32\.exe|services\.exe|powershell\.exe|pwsh\.exe|regs...
22
process_nameregex_match
(?i)\x5csystem32\x5c(lsass|services)\.exe
22
process_nameregex_match
(?i)\x5csystem32\x5cspoolsv\.exe
22
CallerProcessNameends_with
\checkadmin.exe
1
CommandLinecontains
-exec bypass -enc jgag
1
CommandLinecontains
/create
115
CommandLinecontains
audiodg
1
CommandLinecontains
conhost
1
CommandLinecontains
dwm.exe
1
CommandLinecontains
explorer
1
CommandLinecontains
lsass
1
CommandLinecontains
lsm
1
CommandLinecontains
mmc
1
CommandLinecontains
msiexec
12
CommandLinecontains
regsvr32
1
CommandLinecontains
rundll32
13
CommandLinecontains
services
1
CommandLinecontains
spoolsv
1
CommandLinecontains
svchost
1
CommandLinecontains
taskeng
1
CommandLinecontains
taskhost
1
CommandLinecontains
wininit
1
CommandLinecontains
winlogon
1
CommandLinecontains
/tn win32times /f
1

Exclusions (79 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. 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. Click a value to expand the rules under this technique that exclude it.

FieldKindValueRules excluding
parent_process_namematch
^-$
4
Imagewildcard
c:\program files (x86)\*.exe
2
Imagewildcard
c:\program files\*.exe
2
ParentImageeq
c:\windows\system32\svchost.exe
2
parent_process_nameeq
MpCmdRun.exe
2
parent_process_nameeq
MsMpEng.exe
2
parent_process_nameeq
cmd.exe
2
parent_process_nameeq
node.exe
2
parent_process_nameeq
powershell.exe
2
parent_process_nameeq
svchost.exe
2
parent_process_nameregex_match
(?i)services\.exe|\%14\NOT S\!
2
parent_process_nameregex_match
(?i)wininit\.exe
2
process.argswildcard
*C:\WINDOWS\temp\nessus_*.tmp*
2
process.argswildcard
*C:\WINDOWS\temp\nessus_*.txt*
2
process_nameeq
gpupdate.exe
2

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.

Platform (all)
Domain (all)

Sigma 3 rules

Elastic 5 rules

Splunk 9 rules