Obfuscated Files or Information: Steganography T1027.003

Tactic: Stealth

Adversaries may use steganography techniques in order to prevent the detection of hidden information. Steganographic techniques can be used to hide data in digital media such as images, audio tracks, video clips, or text files.

Events covered

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

ProviderEventTitle
SysmonEvent ID 1Process creation
Linux-AuditdEvent ID 1309EXECVE

Authoring guide

Patterns shared across the 5 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 (9 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
a04eq 4steghide, cat, unzip
a14ends_with 2, eq 2.jpg, .png, embed, extract
type4eq 4EXECVE
a23eq 2, ends_with 1-cf, -ef, -sf, .zip
CommandLine1ends_with 1.lnk, .lnk", .lnk'
Image1ends_with 1\find.exe, \findstr.exe
OriginalFileName1eq 1find.exe, findstr.exe
a31ends_with 1.jpg, .png
a41eq 1-cf, -ef

Top indicator values (23 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
typeeq
EXECVE
428
a0eq
steghide
22
a0eq
cat
1
a0eq
unzip
1
a1ends_with
.jpg
23
a1ends_with
.png
23
CommandLineends_with
.lnk
1
CommandLineends_with
.lnk"
1
CommandLineends_with
.lnk'
1
Imageends_with
\find.exe
18
Imageends_with
\findstr.exe
112
OriginalFileNameeq
find.exe
17
OriginalFileNameeq
findstr.exe
112
a1eq
embed
1
a1eq
extract
1
a2ends_with
.zip
1
a2eq
-cf
1
a2eq
-ef
1
a2eq
-sf
1
a3ends_with
.jpg
12
a3ends_with
.png
12
a4eq
-cf
1
a4eq
-ef
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.

Platform (all)
Domain (all)

Sigma 5 rules