Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0bf8276841c6bc7a…

MALICIOUS

RTF / .DOC

5.2 KB
MD5: eb32197db29e9d9588b3c5520ba8f2a5 SHA-1: 5428a10647e6a2f247f271ad85c82e03cf5679c7 SHA-256: 0bf8276841c6bc7adc17d84962d1e380344f711c98f4e107938f204daca62c0d
200 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 allows for arbitrary code execution upon opening the document, likely leading to the download and execution of a secondary payload.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000009a.bin
bef088d4efd604d27f190236dd3b392df31015e912c748cb34852423577ed765
rtf-objdata-decoded RTF \objdata at offset 0x9A 2421 bytes