Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a0f6efe4b4c547a2…

MALICIOUS

RTF / .DOC

3.9 KB First seen: 2022-05-23
MD5: a1b9b253f428c5dba1a19de9b8019387 SHA-1: 1e3c248adb37ae7fdf4233cc76d2aa0a6c934f95 SHA-256: a0f6efe4b4c547a2c4bc06b8bd7289f58e680703b695b2b69909f46eb967035b
160 Risk Score

Malware Insights

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

The RTF document contains embedded OLE objects, specifically triggering critical heuristics related to the Equation Editor vulnerability. The presence of \objupdate further indicates that the embedded object is designed to be activated automatically, likely leading to the execution of malicious code. This points to a classic exploit delivery mechanism targeting the Equation Editor component.

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_off0000008e.bin
ac9fbe51ca8cf0a4f905ededdaec2b97a7a599e738b0cda04619333608356d1c
rtf-objdata-decoded RTF \objdata at offset 0x8E 1650 bytes