Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6e5d7060a4837ebb…

MALICIOUS

RTF / .DOC

25.7 KB
MD5: 530149477823e09b8b4dd0cf902458f7 SHA-1: 2c4fe9921a63faab0f64243f3406ca3f4b6f2f8d SHA-256: 6e5d7060a4837ebb99509241c5e8342c13e8055d6777286d2c8f26bc0409d55e
180 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE object data, specifically triggering the CVE-2017-11882 vulnerability related to Microsoft Equation Editor. This exploit allows for arbitrary code execution, which is typically used to download and run a second-stage malicious payload. No specific family could be identified from the available evidence.

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_off000016ab.bin
6554c1b645ced4146b420870b14cff3221fdb7c19c7202f4d0a67667cea8a4fe
rtf-objdata-decoded RTF \objdata at offset 0x16AB 1345 bytes