Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1b0cc85158b8c798…

MALICIOUS

RTF / .DOC

89.1 KB First seen: 2023-09-28
MD5: 2ec503e03a0e68f21c07b4160e735e19 SHA-1: 3ada41f3149a4ced9a6d3dd04529e3134e794e76 SHA-256: 1b0cc85158b8c798165524c56c84c858af1bed6b437e463edf372446ba221a6a
160 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object and specifically targets the Equation Editor vulnerability. The 'SE_ENABLE_LURE' heuristic indicates the document instructs the user to enable editing, a common tactic for macro-based malware droppers. The presence of RTF-specific heuristics like RTF_OBJDATA, RTF_OBJEMB, and RTF_EQUATION_EDITOR strongly suggests an exploit targeting Microsoft Office's Equation Editor component.

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.
  • \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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off000065f2.bin
7c72ce14e950222aad6d86ae8d20d6b6e16525985919faa1645e8b3d4c958ad9
rtf-objdata-decoded RTF \objdata at offset 0x65F2 1602 bytes