Malicious RTF — malware analysis report

Static analysis result for SHA-256 63b80f917e968fe4…

MALICIOUS

RTF

37.9 KB First seen: 2023-07-24
MD5: 4ffa1725940a634a2eef3bed85ea9bd7 SHA-1: 5aca95bb2489e478d6fb44fac8c85721f5b6fc5a SHA-256: 63b80f917e968fe46f8c892d725e7bf65236681e8b9d864e141a4ca0aadd8abf
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object and an ".objupdate" directive, strongly suggesting an attempt to exploit a vulnerability, likely within the Equation Editor component, as indicated by the 'RTF_EQUATION_EDITOR' heuristic. The 'SE_ENABLE_LURE' heuristic further supports that the document's content is designed to trick the user into enabling editing, which would trigger the OLE object's activation and potential exploitation.

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_off000040aa.bin
bfee5e759cd96a4e268d0d54c16bd78133d0849178eb96a02c033b453554a186
rtf-objdata-decoded RTF \objdata at offset 0x40AA 1593 bytes