Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5d77fcbee204c6b9…

MALICIOUS

RTF / .DOC

4.2 KB
MD5: e205f10f887754bd65281f14c25c0f21 SHA-1: b356aab56ba5eb993326e4ede7e254e7181aa165 SHA-256: 5d77fcbee204c6b9fea6ec4bda5216714e2e46f4247f673956e64e36a9c3424d
180 Risk Score

Malware Insights

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

The RTF document contains embedded OLE object data, specifically related to the Equation Editor. Heuristics indicate a high likelihood of exploitation for CVE-2017-11882, which allows for arbitrary code execution. The presence of ".objupdate" further suggests an attempt to force OLE activation and trigger the exploit. This is a common method for delivering malicious payloads via email attachments.

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_off000000d2.bin
78b8862cfbc61e0d595bd229107b15d64269ba499ba47250d9ace637fc9633f2
rtf-objdata-decoded RTF \objdata at offset 0xD2 1838 bytes