Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f89021befe611896…

MALICIOUS

RTF / .DOC

33.6 KB First seen: 2023-05-22
MD5: c460a03f63c3c77e60c5af1f792ac6d2 SHA-1: 6ee8a67afdac5a6fd9e4645626685105a5c84f76 SHA-256: f89021befe6118964b05a284f93655371379e3cd86803b5659b62b35a1bba290
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 an Equation Editor ProgID, and an \objupdate directive that forces OLE activation. The document body contains a lure instructing the user to 'Enable editing', a common tactic for macro-based malware droppers. The presence of these elements strongly suggests an exploit targeting the Equation Editor vulnerability.

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_off000047d8.bin
3befd7b394bd80cad00aa2cdd6a2f0eef19b28c99b58179a21a9275dd0ff99ff
rtf-objdata-decoded RTF \objdata at offset 0x47D8 1473 bytes