Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f22f0f42d468f655…

MALICIOUS

RTF / .DOC

42.9 KB First seen: 2023-05-10
MD5: dc566b1ea8709d61642c3641d1109708 SHA-1: cce442e2d4ea7c3368387f9f02bfc1d37f9b0008 SHA-256: f22f0f42d468f65578d438395e6c9bd9505e086761471b4ef45ee7779b4595f9
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to force OLE activation, and the SE_ENABLE_LURE heuristic suggests the document contains instructions to enable content. This combination strongly indicates a malicious document designed to exploit Equation Editor to achieve code execution, likely for downloading further stages.

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_off000055f1.bin
73e65aa53dd43f3308572f95380ad5442f7750669af57c2e01ebd29b757638e0
rtf-objdata-decoded RTF \objdata at offset 0x55F1 1997 bytes