Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 54a97b0833c81df8…

MALICIOUS

RTF / .DOC

38.7 KB First seen: 2023-04-20
MD5: 497868c92b2ff34e3220398b236a01d6 SHA-1: 6b483ae85e9bc0128ea6fc975a05f74992397542 SHA-256: 54a97b0833c81df8a0889289119e5662abdeb6eb35f98e38cb63f2acf5b36a19
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a specific Equation Editor ProgID, triggering critical heuristics. The ".objupdate" directive indicates an attempt to force OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests an exploit targeting the Equation Editor vulnerability to execute a malicious 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_off00005130.bin
30c2457aa0fa0cd61f1fbc5a07a3e683ca09b6dd8fce3bad7abd0a03afa06851
rtf-objdata-decoded RTF \objdata at offset 0x5130 1385 bytes