RTF malware analysis — malicious · c43573c00d28db37

MALICIOUS

RTF

364.2 KB First seen: 2019-02-10

MD5: 216b10a519ff0d82f876a3ebfeedc96a SHA-1: c8b416dd1eac5842579f7aeb22ea7ad5af8eb702 SHA-256: c43573c00d28db37fd08b5c8f7d01cce9eb7a173e7997d8f12de65bd70b920d5

344 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, a composite moniker, and a PE header within hex data. Crucially, it exploits CVE-2017-8570, which is known to drop a script file. An extracted artifact, objdata_05_off00006688.bin, is also flagged as suspicious and likely contains the second-stage 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.
ClamAV: Win.Packer.MalwareCrypter-6642003-1 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Win.Packer.MalwareCrypter-6642003-1
PE header (with DOS stub) in hex data critical RTF_MZ_HEX

Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
\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 6 \objdata section(s) — embedded OLE objects
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://nsis.sf.net/NSIS_Error In RTF body

Extracted artifacts 6

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00003af4.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x3AF4	885 bytes
SHA-256: `7d5f88680e60b61c3804b4e958745d940ae073cb6f167cc9e0d1a27e8996ab45`
`objdata_01_off00004211.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x4211	612 bytes
SHA-256: `c62851521e10316dfd43f2b6ee67cc27e2a24456bb346c8fa9dc4a6d6e21d526`
`objdata_02_off0000470b.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x470B	464 bytes
SHA-256: `e703848bebd5a70ed3890f101964afa809d470068426f899f139fe667cfa40f0`
`objdata_03_off00004adf.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x4ADF	820 bytes
SHA-256: `d6e0de80a1802cce16fd208d08beb938c29c6d62984b89d9b3f972281ec4f244`
`objdata_04_off000051ae.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x51AE	2633 bytes
SHA-256: `fe11c27d916ab897eb94064e9631d8a29c847a6db39259bef31578da8d19fdf5`
`objdata_05_off00006688.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x6688	173350 bytes
SHA-256: `26b4ec30fd2f6dba329cd3fb936710737889323e342f095e2e22b7c39c189976`
Detection ClamAV: Win.Packer.MalwareCrypter-6642003-1 Obfuscation or payload: likely Carved artifact entropy is 7.85, consistent with packed or encrypted content.

Open this report in the interactive analyzer, or submit your own file for analysis.