Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 df770aabdc39c925…

MALICIOUS

RTF / .DOC

39.6 KB First seen: 2023-02-21
MD5: 2f33e743eb105ce162a713b1b21e429d SHA-1: ba35963190d4f31ca073682f412849970ad7019d SHA-256: df770aabdc39c9255b2eab82391b1246ca57f2108c670fcba0f40b7c46c7ddb7
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The RTF document contains 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 body includes a lure to 'Enable editing', suggesting it's designed to trick users into triggering the exploit. The exploit likely leads to the execution of 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_off000041cc.bin
19874db0bc257daac510cdfc391b44cd1c9e1dc2cc73b6860f48685387c92e61
rtf-objdata-decoded RTF \objdata at offset 0x41CC 1707 bytes