Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 70cc8f537f5ec180…

MALICIOUS

RTF / .DOC

56.8 KB
MD5: b8bdcc29545af3d849706008a36dfc99 SHA-1: d2773080d6e0d15b203d5c30b0e0bdc0bb1cce8f SHA-256: 70cc8f537f5ec180a01c2ba94066bf4fc9363f6e270bd76bd33834c841480440
120 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE objects and specifically targets the Equation Editor vulnerability. The presence of \objupdate indicates that the embedded object is designed to be activated automatically, leading to code execution. This is a common technique for delivering secondary payloads, although no specific payload or C2 infrastructure was identified in this analysis.

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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000007a2.bin
4f3b500bc8cf0c143a97467f0b155ab9f0f115d80ef06e892098f43b3b66345f
rtf-objdata-decoded RTF \objdata at offset 0x7A2 1927 bytes