Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 58dbc1d3aa2985f9…

MALICIOUS

RTF / .DOC

13.2 KB
MD5: 250347536c0f798fa8f9d21399a8762e SHA-1: edf378b151affbe5cab646b606176b6686e4551e SHA-256: 58dbc1d3aa2985f91ef6cc60c5d64d9e47c2f3cd2c3b1c81da69ae938fe98bc5
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a ProgID indicative of Equation Editor, triggering the CVE-2017-11882 exploit. The presence of ".objdata" and ".objupdate" sections further confirms the attempt to activate and execute the embedded object. This exploit is commonly used to deliver second-stage payloads.

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_off00000d47.bin
5d435661fcb9550bcb8595fd0aefdd483e9acded4f8f56fe2fae6590ad5b9901
rtf-objdata-decoded RTF \objdata at offset 0xD47 2160 bytes