Malicious RTF — malware analysis report

Static analysis result for SHA-256 2c96da2df769f6bd…

MALICIOUS

RTF

1.75 MB First seen: 2019-05-16
MD5: 0836f944d3f0d24d36044f0f56ac878c SHA-1: 453657769dadfeeec379e129b0d05f294474c17a SHA-256: 2c96da2df769f6bd472a4e4cd0858379c29257e2aeec8d08a752058a9377d933
224 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains multiple indicators of malicious activity, including OLE object data and composite monikers related to CVE-2017-8570. This vulnerability is known to be used for dropping and executing script files. The presence of a large, high-entropy extracted artifact (objdata_01_off000001ee.bin) suggests it likely contains the dropped 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 ~1755KB 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 877774 bytes
SHA-256: 13d8f01de9833e115ba6017589ff8a7a8cbbcebfd148fdae9ebd0286a2174a45
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.83, consistent with packed or encrypted content.
objdata_02_off001ae609.bin rtf-objdata-decoded RTF \objdata at offset 0x1AE609 990 bytes
SHA-256: 819742f5c84cbe7b646f281a2d66b550ab90b6860c2f5bde5cdca478f30b59a9
objdata_03_off001aedfe.bin rtf-objdata-decoded RTF \objdata at offset 0x1AEDFE 26316 bytes
SHA-256: 606145c7bfce5c000729bc1389ffd6453bd3c033f89d75e214b4a3ab94781620
objdata_04_off001bbbce.bin rtf-objdata-decoded RTF \objdata at offset 0x1BBBCE 380 bytes
SHA-256: 17e63036be0dbac77e35be89dbbfbf4e8c5055136fd574d2fd6018a721b22af7
objdata_05_off001bbf02.bin rtf-objdata-decoded RTF \objdata at offset 0x1BBF02 882 bytes
SHA-256: e0dd860bb62dee2108b913a024deb7f63abfad8765c6af0041159382d16d8717
objdata_06_off001bc664.bin rtf-objdata-decoded RTF \objdata at offset 0x1BC664 2633 bytes
SHA-256: fe11c27d916ab897eb94064e9631d8a29c847a6db39259bef31578da8d19fdf5
objdata_07_off001bdb7c.bin rtf-objdata-decoded RTF \objdata at offset 0x1BDB7C 2601 bytes
SHA-256: 67ff079a9b0f053ca2843811d9da7a8fdedc7d9d377ef39d09dde148b9657c7f