Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ddff7800ee0f9035…

MALICIOUS

RTF / .DOC

95.4 KB First seen: 2023-10-25
MD5: f50825584a3ee5441402a9003ef6ca2f SHA-1: 06236c8c734c54e648a2b88765b54a950a9c8cc7 SHA-256: ddff7800ee0f903505387e417813ecfa9ebf9023740e59380c34ee8f29aa156e
180 Risk Score

Malware Insights

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

The sample is an RTF document exploiting the Equation Editor vulnerability (RTF_EQUATION_EDITOR). It contains OLE object data and an ".objupdate" directive, indicating an attempt to automatically activate embedded objects. The document body includes a lure instructing the user to 'Enable editing' to bypass security measures, strongly suggesting a malicious intent to execute a payload.

Heuristics 5

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00002b18.bin
55416e088082186557045058c552369dd75efe7021ec43c3e01e65f23b5f7c24
rtf-objdata-decoded RTF \objdata at offset 0x2B18 1460 bytes