Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c1cd4a1045851e4f…

MALICIOUS

RTF / .DOC

21.6 KB First seen: 2022-11-07
MD5: ba08e120a89aebcaa0f74d3182dc9138 SHA-1: 0f24caa03828cd933367ce66d111d2707d40d037 SHA-256: c1cd4a1045851e4f1abd489ca80fe24188079a20d92b0151e98c4de7e18086e2
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1059.005 Service Execution

The RTF document contains an OLE object with an Equation Editor ProgID, a known exploit vector. The presence of \objupdate suggests an attempt to force OLE activation, likely to trigger the embedded exploit. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic for macro-based malware droppers to bypass security settings.

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_off00004142.bin
fff3eace4bf9fc1573bbd25e1aad4ca033a687fdd3c91a5d738641926a94a05c
rtf-objdata-decoded RTF \objdata at offset 0x4142 1515 bytes