MALICIOUS
522
Risk Score
Malware Insights
MITRE ATT&CK
T1203 Exploitation for Client Execution
T1566.001 Spearphishing Attachment
The RTF file contains multiple critical heuristic firings indicating exploitation of CVE-2017-11882 and CVE-2017-8570 through the Equation Editor. These vulnerabilities are known to be used for dropping secondary payloads. ClamAV detection confirms this as Win.Dropper.Fareit, a known dropper family. The embedded objdata_02_off000165a2.bin is likely the dropped payload.
Heuristics 12
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Composite Moniker — CVE-2017-8570 (drops SCT script) critical CVE_2017_8570RTF \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.
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Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOREquation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
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CVE-2017-11882/0802 — suspicious Equation font record high CVE likely CVE_2017_11882RTF contains Equation Editor data with an anomalous MTEF font record shape. This is a static indicator for Equation Editor font-record overflow CVE families, stronger than CLSID presence.
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Composite Moniker in RTF OLE object high RTF_COMPOSITE_MONIKER_RELATEDRTF 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.
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ClamAV: Win.Dropper.Fareit-6680868-0 critical CLAMAV_DETECTIONClamAV detected this file as malware: Win.Dropper.Fareit-6680868-0
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PE header (with DOS stub) in hex data critical RTF_MZ_HEXHex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
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\objupdate forces OLE activation high RTF_OBJUPDATERTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
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Large hex data blocks in OLE object high RTF_EXCESSIVE_HEXRTF contains ~1346KB of hex-encoded data inside \objdata sections — may hide a payload
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OLE object data medium RTF_OBJDATARTF contains 7 \objdata section(s) — embedded OLE objects
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OlePres presentation stream in RTF OLE object medium RTF_OLEPRES_STREAMRTF contains an embedded OLE object with an OlePres presentation stream. OlePres is an OLE presentation marker and is not enough on its own to identify CVE-2025-21298.
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Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGEOne 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.
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Embedded URL info EMBEDDED_URLOne 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 7
Files carved from inside the sample during analysis.
| Filename | Kind | Source | Size |
|---|---|---|---|
objdata_00_off0000002c.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x2C | 884 bytes |
SHA-256: 08cb831cfd094f7193857584f98ebb419e336c73f0191f78a94fb322b6fcad85 |
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objdata_01_off00005f41.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x5F41 | 33559 bytes |
SHA-256: a1cd204187d3969a56ef0de9c9edeed485f313bdb6eeb1b0ba1a700926216e78 |
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objdata_02_off000165a2.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x165A2 | 627916 bytes |
SHA-256: b69f469ad90210aff1e549bbce1fba57df85c5f8f755f16d4757ae783e792da4 |
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Detection
ClamAV:
Win.Dropper.Fareit-6680868-0
Obfuscation or payload:
likely
Static shellcode analysis found candidate code region(s). Indicators: SC_MSF_REVERSE, SC_STR_VIRTUALALLOC, SC_STR_LOADLIBRARY Static shellcode analysis recovered API/import strings: LoadLibraryExA, VirtualAlloc, GetProcAddress, ExitProcess, CreateThread, VirtualProtect
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objdata_03_off00148f78.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x148F78 | 382 bytes |
SHA-256: 7c829894502990522aaee3764e10dad03b3c7476dec48c4e1d128bb9b9774910 |
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objdata_04_off001492a8.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x1492A8 | 789 bytes |
SHA-256: 87caf099a20fd4563d975979583365d98bc376a5fd992193cf5da7686fc18198 |
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objdata_05_off00149939.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x149939 | 2633 bytes |
SHA-256: 1feb5f150bb35566d1a01fc59a357dc0ea34bc7498e0ec99bd939f6f848044b0 |
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objdata_06_off0014ae43.bin |
rtf-objdata-decoded | RTF \objdata at offset 0x14AE43 | 4679 bytes |
SHA-256: 0e2ce9d01b0df41beca1d9d003ff4bfe3998a96192a53992dd35145a081e0a27 |
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