Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f54229e39a2b3b55…

MALICIOUS

RTF / .DOC

3.7 KB
MD5: 81328cb4752e4a26c4a0f9f28ef2644b SHA-1: b32baa01d3d0b9d740f14af4ee4944cad4e16380 SHA-256: f54229e39a2b3b55eca168f9c0bb6afc072db8f482b047d7236c9f4d282e965e
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

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 the exploitation of the Equation Editor to execute arbitrary code. No document body text or scripts were extracted, but the heuristics strongly indicate a classic Equation Editor exploit.

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_off0000009c.bin
e72c8b0a2938f5dc0bc3e4102369ee94d453716b4dda8995e085b9c466e73bac
rtf-objdata-decoded RTF \objdata at offset 0x9C 1690 bytes