Malicious RTF — malware analysis report

Static analysis result for SHA-256 88e64d1ee5cef931…

MALICIOUS

RTF

1.51 MB Created: 2019-09-17 13:59:00 First seen: 2020-06-01
MD5: fef68253a07f24b3beeba5cd593d8015 SHA-1: 73dcefdeb58315dc3419db9d1cb0ca896024c271 SHA-256: 88e64d1ee5cef931675d670121566e2d8d2509b4c410d710353a3702821c5598
162 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that is configured to update upon activation, leveraging the CVE-2017-8759 vulnerability. This indicates an attempt to execute arbitrary code, likely to download and run a further stage. The presence of shellcode API strings in a statically extracted artifact further supports this. No specific family could be identified.

Heuristics 6

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • \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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00175a72.bin rtf-objdata-decoded RTF \objdata at offset 0x175A72 1414 bytes
SHA-256: 8df2362c819644a88516a3bdf8fa2c18ae8cc040f0e13b30f2c2e7bcae12451a
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis found candidate code region(s). Indicators: SC_STR_LOADLIBRARY, SC_STR_URLDOWNLOAD, SC_PEB_ACCESS Static shellcode analysis recovered API/import strings: LoadLibraryW, GetProcAddress, URLDownloadToFileW, ExitProcess