Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bf335e327480e145…

MALICIOUS

RTF / .DOC

69.0 KB First seen: 2023-09-21
MD5: ff9f274f793df8829cfa6b586b9430f2 SHA-1: b0d3eaca6ea1bcf6ae7dbc7ede7d528c9d5a95d3 SHA-256: bf335e327480e1455c9b20342a51cfdcfd1b3cff7fa515f5db7d7ec193b7840d
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document containing an embedded OLE object, specifically identified as a potential Equation Editor exploit. The document body contains a lure instructing the user to 'enable editing' to bypass security measures. This combination strongly suggests the document is designed to exploit vulnerabilities in Microsoft Office applications via the embedded OLE object, likely to download and execute a secondary payload.

Heuristics 5

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00003dc7.bin
16b7642e93912f2569680e9272c1d889553b99611162eb516a6500ac09bcb09d
rtf-objdata-decoded RTF \objdata at offset 0x3DC7 1467 bytes