Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b54a82cc8d207471…

MALICIOUS

RTF / .DOC

32.1 KB First seen: 2023-05-05
MD5: a992ef43a1b6e6995b54982039b6baa6 SHA-1: 22793173cc663bbc52d4576903a47dafdade2c90 SHA-256: b54a82cc8d20747114d7cb699c85315f69ffe48d906528041f9a58408e2c0ff2
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to force OLE activation, and the SE_ENABLE_LURE heuristic confirms the document instructs the user to enable editing, a common tactic for malware droppers. No scripts were extracted, and the document body content is unrelated to the malicious functionality.

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_off0000579f.bin
10666a0f7a01532ffa4386763c55b3c092617b5a9f0bdede7c828d432a17aab4
rtf-objdata-decoded RTF \objdata at offset 0x579F 1732 bytes