Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9a5b06ce5294bdf5…

MALICIOUS

RTF / .DOC

25.1 KB First seen: 2023-01-16
MD5: 124ccb169d50c3a8a25f161f1bd9a524 SHA-1: 6828f3ae01773760729f24867f987b8d806ee895 SHA-256: 9a5b06ce5294bdf5fa0908ce3204fb59b8ae2b7ad96ae844a0bb21b70d501557
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 split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The \objupdate directive forces OLE activation, and the document includes a lure to enable editing, common for malware droppers. No specific family could be identified from the available evidence.

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_off00004b1b.bin
923f3d2beca37e526f0c9f3283ebda1acef4c4beeda8a47917e61d5f91cd08ec
rtf-objdata-decoded RTF \objdata at offset 0x4B1B 1878 bytes