Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 194df463b3795e85…

MALICIOUS

RTF / .DOC

41.1 KB First seen: 2023-02-21
MD5: 38eb99782693834506cbdcc60ee612c2 SHA-1: ba0bdddb14a4e6d315f9f1103e846500cc77589d SHA-256: 194df463b3795e851b230399d08a63717af9c4320366aba5f8dd191eed3aa43c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object with a specific Equation Editor ProgID, a known exploit vector. The \objupdate directive forces activation of this object upon opening, and the SE_ENABLE_LURE heuristic indicates the document prompts the user to enable editing, which is necessary to trigger the exploit. The embedded object itself is a decoded RTF payload.

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_off000047a7.bin
7a8e5f684ca8862968a4a41477ae5d20425f19e208d3b668fe571cab5b393431
rtf-objdata-decoded RTF \objdata at offset 0x47A7 1783 bytes