Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 15b1bfa049c319bd…

MALICIOUS

RTF / .DOC

24.6 KB First seen: 2022-11-28
MD5: 6d23cdf763fa9e13fec4278bc539f1d2 SHA-1: 2270625e2c1f20aa3777df3af715ebb3cbfbbdfe SHA-256: 15b1bfa049c319bd83403ac8ee54458c8d4b9b1952a5b3bffd0bd0e51ad61199
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 to 'Enable editing'. This suggests the file is designed to exploit the Equation Editor vulnerability to execute a payload.

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_off00004d3b.bin
0eba8dddf962ec7375afe39b9469e77acd02726fdd8e885b2e67233dcd76b808
rtf-objdata-decoded RTF \objdata at offset 0x4D3B 1540 bytes