Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3ee5f99290977ece…

MALICIOUS

RTF / .DOC

32.7 KB
MD5: 5bbe5087bcf52eb82ce8aecb37b51c35 SHA-1: f801e13407b23ebb2ee056e45729abd7105b434a SHA-256: 3ee5f99290977ece3b41d824eefee491b8bcb204d47328a8485fac116824c127
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The sample is an RTF document that contains OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability. The \objupdate directive indicates that the embedded OLE object is intended to be activated, which is a common method for exploiting Equation Editor to achieve arbitrary code execution. The extracted objdata file is likely the payload or a component thereof. This suggests a malicious document designed to exploit this known vulnerability for initial access.

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_off00000612.bin
19d0cc8c3a9e09e3680bbf3d887880385db4c71e59e46a522979f6687726221d
rtf-objdata-decoded RTF \objdata at offset 0x612 2147 bytes