Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3ec37a38b4c0b5d0…

MALICIOUS

RTF / .DOC

4.4 KB
MD5: 3c822f6bdeb2ee0a552a91dda99c644c SHA-1: 41461992211084f1fcfd9192d07e184abb0adf71 SHA-256: 3ec37a38b4c0b5d0817cfc4b4947e9dc16f283bd923cfb4e819cf826f37957c6
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF document contains embedded OLE objects and specifically triggers the Equation Editor vulnerability. The presence of ".objdata" sections and the critical RTF_EQUATION_EDITOR heuristic firing strongly indicate exploitation of a known Equation Editor flaw. The ".objupdate" heuristic suggests that the embedded object is designed to be activated automatically, leading to arbitrary code execution.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000ca.bin
3eeadf5621a650f27cad175deaa49fe79b941318ea4f0dde7410a0a443704a98
rtf-objdata-decoded RTF \objdata at offset 0xCA 2020 bytes