Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 147cde1eaad1c3e1…

MALICIOUS

RTF / .DOC

3.5 KB
MD5: d72188da23e88358073796fa0e71a9a8 SHA-1: 108112041a6c33bb7467e7aadcb2a6228fe15007 SHA-256: 147cde1eaad1c3e10705c0e5589f696ebd676ec13fed6d8790b7f4ea326a9379
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains embedded OLE object data, specifically related to Equation Editor. Heuristics indicate a critical firing for RTF_EQUATION_EDITOR and high firings for CVE_2017_11882_ACTIVATION_RELATED and RTF_OBJUPDATE, strongly suggesting exploitation of the CVE-2017-11882 vulnerability. This vulnerability allows for arbitrary code execution upon activation of the embedded object.

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_off000000a4.bin
a9c47ed21685f7749588ee8fcb9c8750e57aefb66f146ce8ad1ad05e9bd73e6b
rtf-objdata-decoded RTF \objdata at offset 0xA4 1458 bytes