Malicious RTF — malware analysis report

Static analysis result for SHA-256 4606be3e246c899c…

MALICIOUS

RTF

3.5 KB
MD5: 5fd1ce532ddf6ab0ce29041d1e4cf8f3 SHA-1: b137531df710d40ff3f6ce590c6e25fdb95b635d SHA-256: 4606be3e246c899c950b5108149d21f7f134e7fc4612744693294e62ecae1b44
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 Microsoft 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 that the embedded object is intended to be activated, leading to the execution of malicious code.

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_off000000d0.bin
124d767aebd674018e012b8ad2d70ac5c1fddb411b256143367f93c5cf9b9d17
rtf-objdata-decoded RTF \objdata at offset 0xD0 1495 bytes