Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e276df4abf341b55…

MALICIOUS

RTF / .DOC

19.6 KB First seen: 2022-10-05
MD5: 24bf977086e6a528df15a66f948b05e9 SHA-1: d03270e51de55f19eee10dd4d719f1a16847b896 SHA-256: e276df4abf341b55ad5b90f745f365fe6a44eaec3e2ee124a1dbe1c4f29e1788
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1566.002 Phishing: Spearphishing via Service

The file is an RTF document that contains an embedded OLE object, specifically an Equation Editor exploit. The `\objupdate` directive forces the activation of this object, which is a known technique for delivering malicious payloads. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures and execute embedded exploits.

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_off00001ccd.bin
29dddbfa1ac8e205e48beef86d597ad6be768db102b57da29fffea0f96892a25
rtf-objdata-decoded RTF \objdata at offset 0x1CCD 1945 bytes