ATT&CK coverage › Technique

Defacement T1491

Adversaries may modify visual content available internally or externally to an enterprise network, thus affecting the integrity of the original content. Reasons for Defacement include delivering messaging, intimidation, or claiming (possibly false) credit for an intrusion. Disturbing or offensive images may be used as a part of Defacement in order to cause user discomfort, or to pressure compliance with accompanying messages.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon11FileCreate
Sysmon13RegistryEvent (Value Set)

Authoring guide

Patterns shared across the 2 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 (5 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
Image2ne 2"*\\explorer.exe", "*\\Windows\\Explorer.EXE"
Details1in 1"*\\users\\public\\*", "*\\temp\\*"
TargetObject1in 1"*\\Control Panel\\Desktop\\WallpaperStyle", "*\\Control Panel\\Desktop\\Wallpaper"
EventID1eq 113
TargetFilename1eq 1"*\\AppData\\Roaming\\Microsoft\\Windows\\Themes\\Transco...

Top indicator values (8 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
EventIDeq131
Imagene"*\\explorer.exe"1
TargetObjectin"*\\Control Panel\\Desktop\\Wallpaper"1
Detailsin"*\\users\\public\\*"1
TargetObjectin"*\\Control Panel\\Desktop\\WallpaperStyle"1
Detailsin"*\\temp\\*"1
TargetFilenameeq"*\\AppData\\Roaming\\Microsoft\\Windows\\Themes\\TranscodedWallpaper"1
Imagene"*\\Windows\\Explorer.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.

Splunk 2 rules