Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 456c52ec92e16402…

MALICIOUS

RTF / .DOC

5.0 KB First seen: 2022-07-22
MD5: 9532b1e22e9e15019a35b27f75292d04 SHA-1: 8e87d556efaca091a0c76e3af7b79cbd6af8f409 SHA-256: 456c52ec92e1640209de9fdedadb172c2689e7d8e590941dcdfb318019662418
120 Risk Score

Malware Insights

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

The sample is an RTF document containing embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability. This indicates the file is designed to exploit CVE-2017-11882, a known vulnerability allowing for arbitrary code execution when the embedded object is activated. The RTF structure and the specific heuristics strongly suggest a malicious document intended for exploitation.

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_off00000080.bin
79b9468f40fa2e85910d0fb25b5c2a58520e5679dcb3af1fe417fa4dc1276431
rtf-objdata-decoded RTF \objdata at offset 0x80 2148 bytes