Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e531e6945506af38…

MALICIOUS

RTF / .DOC

37.5 KB First seen: 2023-04-21
MD5: 41395474d95e6d0baa9c74d722ed1977 SHA-1: b16bb18d403da7cf9e4b8c9f4bf78dcd97f0518b SHA-256: e531e6945506af38e26e812faa2afd82a6f721c9bc4183a33ebcba3496ee1397
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The \objupdate directive forces OLE activation, and the document body includes a lure instructing the user to 'Enable editing'. This combination strongly suggests a malicious document designed to exploit the Equation Editor vulnerability upon opening.

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.
  • \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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005566.bin
a84e07a02d48760eb487840c2d1745d175a5873d94da1e7714ef1377a20d843c
rtf-objdata-decoded RTF \objdata at offset 0x5566 1656 bytes