Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f044f41a42acafbd…

MALICIOUS

RTF / .DOC

64.6 KB First seen: 2023-07-19
MD5: 995d9b5943c9dfc62358b43fc03ebba4 SHA-1: 5533c63d995ad3d7a704af136e5bafa8f4bcdeee SHA-256: f044f41a42acafbdec681455adb91b3c25de8cc815917f953efe9a326dbbd898
120 Risk Score

Malware Insights

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

The sample is an RTF document containing OLE object data and specifically triggers heuristics for the Equation Editor vulnerability. The \objupdate directive indicates that the embedded OLE object will be activated automatically, leading to exploitation. This is a common delivery mechanism for malware that aims to download and execute further stages.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000062e.bin
29f12063dcff3cb3833351d36075144c0fa565124d70f25748cfc0011d19af46
rtf-objdata-decoded RTF \objdata at offset 0x62E 19475 bytes