Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 55df8e9dada4df1e…

MALICIOUS

RTF / .DOC

33.7 KB First seen: 2023-05-16
MD5: 54fec9c648ca8fb236a1b99e02a1e07a SHA-1: 446277f5f6088d3731b296eff118220b059533cd SHA-256: 55df8e9dada4df1e4bc5e5f7022de2e6153edcbe00a585bde840020a71ae3fc4
180 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File

The RTF document contains an OLE object with a split Equation Editor ProgID and is configured to automatically update and activate. This is a common technique to exploit vulnerabilities in Microsoft Office, such as CVE-2017-11882, to execute arbitrary code. The document body contains a lure instructing the user to 'Enable editing', further supporting the malicious intent.

Heuristics 5

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off000043c0.bin
61285d25c153faa2490f40cc1ae613011bef3978ca3c41278437d7495260a91e
rtf-objdata-decoded RTF \objdata at offset 0x43C0 1565 bytes