Malicious RTF — malware analysis report

Static analysis result for SHA-256 4449022e439f3e0d…

MALICIOUS

RTF

2.17 MB First seen: 2019-03-10
MD5: 68ba5e2b643b8fbd6712d432d3f0a802 SHA-1: fb09a6541b3b64be0ead979e362b6eec2f2b3fb2 SHA-256: 4449022e439f3e0df73e17f43a9ae2e5780b09a180f5654769d7d99dd45ad37a
224 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1027 Obfuscated Files or Information

The RTF file contains multiple OLE objects, with a critical finding indicating exploitation of CVE-2017-8570. This vulnerability allows for the dropping of SCT scripts, which are likely used to execute a malicious payload. The presence of excessive hex data within OLE objects further suggests the hiding of a payload.

Heuristics 8

  • Composite Moniker — CVE-2017-8570 (drops SCT script) critical CVE related CVE_2017_8570
    RTF \objdata decodes to OLE data containing the Composite Moniker — CVE-2017-8570 (drops SCT script) CLSID — the vulnerable control/moniker is embedded directly in the document's object stream, the delivery shape of this exploit. RTF objects auto-render when Word opens the file.
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~2203KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 9 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Suspicious extracted artifact info 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/SMI/2005/WindowsSettings In RTF body
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn RTF body

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000025.bin rtf-objdata-decoded RTF \objdata at offset 0x25 205 bytes
SHA-256: 980870ba17beb12f03c3941a0cfa655d820816cec9104090156a6ea6ece5ce8a
objdata_01_off000001ee.bin rtf-objdata-decoded RTF \objdata at offset 0x1EE 1101788 bytes
SHA-256: d38af4dc6fa6a719ad9f86f8c84648d6ebe776f10b062ee70e7b46dcba6b3fa0
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.83, consistent with packed or encrypted content.
objdata_02_off0021a72b.bin rtf-objdata-decoded RTF \objdata at offset 0x21A72B 990 bytes
SHA-256: 819742f5c84cbe7b646f281a2d66b550ab90b6860c2f5bde5cdca478f30b59a9
objdata_03_off0021af20.bin rtf-objdata-decoded RTF \objdata at offset 0x21AF20 26316 bytes
SHA-256: 89d1c0807f4d4dd2dbc3c5357fc9e55a3129223e5915f30eec025828c74b2682
objdata_04_off00227cf0.bin rtf-objdata-decoded RTF \objdata at offset 0x227CF0 380 bytes
SHA-256: 17e63036be0dbac77e35be89dbbfbf4e8c5055136fd574d2fd6018a721b22af7
objdata_05_off00228024.bin rtf-objdata-decoded RTF \objdata at offset 0x228024 882 bytes
SHA-256: e0dd860bb62dee2108b913a024deb7f63abfad8765c6af0041159382d16d8717
objdata_06_off00228786.bin rtf-objdata-decoded RTF \objdata at offset 0x228786 2633 bytes
SHA-256: fe11c27d916ab897eb94064e9631d8a29c847a6db39259bef31578da8d19fdf5
objdata_07_off00229c9e.bin rtf-objdata-decoded RTF \objdata at offset 0x229C9E 2601 bytes
SHA-256: 67ff079a9b0f053ca2843811d9da7a8fdedc7d9d377ef39d09dde148b9657c7f