Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1e3da537b93420e1…

MALICIOUS

RTF / .DOC

17.6 KB First seen: 2022-10-05
MD5: ee3bf91db33c6454ec4418b7e606c65a SHA-1: 6ac4f626f7d5871160aeebb893b06dfea1974b5d SHA-256: 1e3da537b93420e1bdb699c386d0408393df8001f23c000ab203ceec5af958c0
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter

The sample is an RTF document containing an OLE object with a specific Equation Editor ProgID, indicating a known exploit technique. The \objupdate directive forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests the file is designed to exploit vulnerabilities in Microsoft Office to execute arbitrary code, likely as a downloader for further malicious activity.

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_off0000206d.bin
3701d82d27a23985ae57e9c54221cdc5f2e17d10e78a70c32368b1de68882eea
rtf-objdata-decoded RTF \objdata at offset 0x206D 1735 bytes