ATT&CK coverage › Technique

Masquerading: Right-to-Left Override T1036.002

Adversaries may abuse the right-to-left override (RTLO or RLO) character (U+202E) to disguise a string and/or file name to make it appear benign. RTLO is a non-printing Unicode character that causes the text that follows it to be displayed in reverse. For example, a Windows screensaver executable named <code>March 25 \u202Excod.scr</code> will display as <code>March 25 rcs.docx</code>. A JavaScript file named <code>photo_high_re\u202Egnp.js</code> will be displayed as <code>photo_high_resj.png</code>.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon11FileCreate
Security-Auditing4688A new process has been created.

Authoring guide

Patterns shared across the 4 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
CommandLine2match 2tdo.msc, fdp.msc, slx.msc, \u202e,
Image1ends_with 1\mmc.exe
OriginalFileName1eq 1MMC.exe
TargetFilename1match 1nls., tdo., piz.
file_name1regex_match 1, ne 1unknown, "\\x{202E}"

Top indicator values (38 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
CommandLinematchlmth.msc1
Imageends_with\mmc.exe16
CommandLinematchxtpp.msc1
CommandLinematchslx.msc1
CommandLinematchxslx.msc1
CommandLinematchxcod.msc1
CommandLinematchftr.msc1
CommandLinematchfdp.msc1
OriginalFileNameeqMMC.exe12
CommandLinematchcod.msc1
CommandLinematchtdo.msc1
CommandLinematch1
CommandLinematch\u202e1
CommandLinematch[U+202E]1
TargetFilenamematch[U+202E]1
TargetFilenamematchgepj.1
TargetFilenamematch1
TargetFilenamematchvwm.1
TargetFilenamematchfdp.1
TargetFilenamematchism.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 3 rules

Splunk 1 rule