Malicious RTF — malware analysis report

Static analysis result for SHA-256 bfb063bc82802eaa…

MALICIOUS

RTF

19.9 KB
MD5: 87daa273000c61cd0de4624ff8fffa92 SHA-1: a050321cc863e57f32bf0b682f57d75fba0cf4c9 SHA-256: bfb063bc82802eaa6658f4b94e81365871054878a81d352f2d97caf2397ffabd
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link T1059.003 Command and Scripting Interpreter: Windows Command Shell

The file is an RTF document containing embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The presence of \objupdate indicates that the embedded object is designed to be activated automatically upon opening, likely leading to the execution of a secondary payload. While no specific URLs or scripts were extracted, the exploitation of the Equation Editor is a common initial access vector for malware delivery.

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.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d3d.bin
88d0c30ec430d8eee6861b920f3f7e5ee75abdd1589b1eae046861fc1b13728f
rtf-objdata-decoded RTF \objdata at offset 0x1D3D 1715 bytes