Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 691481c563e698b4…

MALICIOUS

RTF / .DOC

115.1 KB
MD5: 204842d2e6ba99b20282a56ccc628f2d SHA-1: c513e2c193c81a085f1be1cf9bf938f3656fd88e SHA-256: 691481c563e698b4c42e1bf7d6ed45495880d401b246a7efd0aaba786256ccca
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF document contains embedded OLE objects, specifically triggering the CVE-2017-11882 vulnerability through the Equation Editor. This exploit is designed to execute arbitrary code upon opening the document, likely as part of a phishing attack.

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_off000000aa.bin
dc3cd301bcdc2c5ed550831cc04cef5580dcc9728ca48dae6d3a4629e15fa63e
rtf-objdata-decoded RTF \objdata at offset 0xAA 33421 bytes