Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6fcd04b25214800c…

MALICIOUS

RTF / .DOC

14.4 KB
MD5: 1d91895b2def45716498f9af9c6dafe7 SHA-1: ff8a1c79b68f83abf628258826e55e87fd726e50 SHA-256: 6fcd04b25214800c0db5d8e27ed501c105e596870aa9321f0f51d21056822ca2
180 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE objects, specifically triggering heuristics related to Microsoft Equation Editor and CVE-2017-11882. This indicates the document is designed to exploit this vulnerability for code execution. The presence of ".objupdate" further suggests an attempt to force OLE activation. Given the exploit, the likely intent is to download and execute a secondary payload.

Heuristics 5

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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_off00001022.bin
b97b31988202bdc9f640b3149a7d9731e24e15de399e16094f9cfabd4b9bd8dc		 rtf-objdata-decoded RTF \objdata at offset 0x1022 1898 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.