Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 78e44c713c7996e7…

MALICIOUS

RTF / .DOC

27.2 KB First seen: 2022-11-14
MD5: 04bd2aa8e81619e40a8b17382c3ae3d5 SHA-1: 8100cee7201baf95de562389189b893ba721f4e2 SHA-256: 78e44c713c7996e742efc871203831bba314f17fcb8e9f87e5935fa7f4826328
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The \objupdate directive forces OLE activation upon opening, and the document body includes a lure to 'Enable editing'. This combination strongly suggests the file is a dropper designed to exploit the Equation Editor vulnerability to execute a malicious 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_off000054b3.bin
44bb0d280d04aa434aee71138b753ec90ff6caa0ef680ac807b7eed94079cbc4
rtf-objdata-decoded RTF \objdata at offset 0x54B3 1742 bytes