Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 517ecc37e62701ad…

MALICIOUS

RTF / .DOC

20.1 KB First seen: 2022-10-12
MD5: 49b0bc3ae35a0475594b42d473a9aa93 SHA-1: 96d60aea15b26586a94f7af642fb13a5ea6d1b70 SHA-256: 517ecc37e62701ad24ae5a80f68038ca1932a8f6b16acca518dbc4190086ffc7
140 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 with a split Equation Editor ProgID, indicating an attempt to exploit CVE-2017-11882. The \objupdate directive forces OLE activation, and the document includes a lure instructing the user to enable editing. This combination strongly suggests the document is designed to exploit the Equation Editor vulnerability to download and execute a secondary payload.

Heuristics 4

  • 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
  • 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_off00001325.bin
08e15053d915a9bb8ebc753a1584fd96299c68a5359b5be150fa5ce8596266c6
rtf-objdata-decoded RTF \objdata at offset 0x1325 1722 bytes