Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e60347491be82017…

MALICIOUS

RTF / .DOC

4.1 KB First seen: 2022-03-11
MD5: d97748075e6ff5fadf97cdc39595b0f1 SHA-1: de0c854a246a6c3c249528bf49298929f8e742ce SHA-256: e60347491be82017565a26ce9b2d803003f93407f1bf455575c8b74b588eba72
121 Risk Score

Malware Insights

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

The RTF document contains embedded OLE object data and specifically triggers the Equation Editor vulnerability. The ".objupdate" directive forces the activation of this embedded object, leading to arbitrary code execution. This is a common delivery mechanism for exploiting older Microsoft Office vulnerabilities.

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_off000000b3.bin
8f670f685854ea994481cfa288e68c4fe4441872a0f3e07965bea45c55f8484e
rtf-objdata-decoded RTF \objdata at offset 0xB3 1875 bytes