Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4caa6577059c1ae8…

MALICIOUS

RTF / .DOC

10.2 KB
MD5: b89adcf60039c044d1164ed53ae30cb9 SHA-1: 2b8ceec18ae46e4e63a1cd6e0b0976c4475541ae SHA-256: 4caa6577059c1ae8904ba3c6d7ce09e59e55ef11917d0368464ddf5a7db66fb6
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The file is an RTF document that leverages the Equation Editor vulnerability. The presence of OLE object data and specific RTF heuristics like RTF_EQUATION_EDITOR and RTF_OBJAUTLINK strongly indicate exploitation of CVE-2017-11882. This vulnerability allows for arbitrary code execution, typically leading to the download and 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.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001200.bin
e22aa649983f8529207f1068f1e6b9e7f2d7315a7c6bb02fc9af40148d74b564
rtf-objdata-decoded RTF \objdata at offset 0x1200 1577 bytes