Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2807f5e1177d1c0c…

MALICIOUS

RTF / .DOC

5.61 MB First seen: 2026-05-13
MD5: 3c350ee1825387fbc18f8f56c49b8795 SHA-1: 4a5a0f842d69ba82fdacd4468274851fba5a3770 SHA-256: 2807f5e1177d1c0ca031fe3dde968177008aa592ba78f23fa43d615367e51aac
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains an embedded OLE object with split hex Equation Editor ProgID and excessive hex data, strongly indicating exploitation of a known Equation Editor vulnerability. The presence of \objupdate further suggests automatic OLE activation, which would trigger the exploit. The large amount of hex-encoded data within the OLE object likely hides a secondary payload, but its specific nature cannot be determined from the provided evidence.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical CVE likely 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~5880KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000105.bin rtf-objdata-decoded RTF \objdata at offset 0x105 2940353 bytes
SHA-256: 18f9722acadcac279832d9a6e241f34a0c7e717bce9f8d3a6dc5fcd1ba6e9680