Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b2ba260b74976bac…

MALICIOUS

RTF / .DOC

36.5 KB First seen: 2023-05-15
MD5: 4255093eaa95334d2ad1d0087fcffc9b SHA-1: de6e8b2e10cf246e3ee61368cf749ccda447f23e SHA-256: b2ba260b74976bac7de34c9ca11678ec4ad197d5e4a16d55e93b69fe7dda33a8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter T1559 Component Object Model Hijacking

The sample is an RTF document that contains an embedded OLE object with a specific ProgID indicating a likely Equation Editor exploit. The \objupdate directive suggests that the embedded object is designed to be activated automatically upon opening the document, which is a common technique for exploiting vulnerabilities like CVE-2017-11882. The document body contains a lure to "Enable editing" to view the content, further supporting the malicious intent.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004d88.bin
0fddfbe47b3b20eb242408d8dedaed515022af8ceab97b0253e5d9fb7136c389
rtf-objdata-decoded RTF \objdata at offset 0x4D88 1580 bytes