Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f2b66ad3130fcdec…

MALICIOUS

RTF / .DOC

19.2 KB
MD5: 0e9c0a82d136c22eeccec8a5752ca4d1 SHA-1: 2a5eb0b1c41b00a1517ea8b7a32252e3733cbd2c SHA-256: f2b66ad3130fcdec9a0e309137ecfbf78780a318697bc73eb8ad605f0d63f5ee
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model

The sample is an RTF document that contains embedded OLE objects, specifically targeting the Equation Editor. Heuristics indicate a high likelihood of exploitation for CVE-2017-11882, which allows for arbitrary code execution when the embedded object is activated. The presence of extasciitilde{}objupdate further suggests that the OLE object is configured to automatically activate.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d5e.bin
4e8be6108adca101f48b9d7a38d6700b80431180f3a07d5c3fe71f0bc4ea709b
rtf-objdata-decoded RTF \objdata at offset 0x1D5E 1769 bytes