Malicious RTF — malware analysis report

Static analysis result for SHA-256 632e2f6696a172df…

MALICIOUS

RTF

2.95 MB Created: 2025-02-13 01:23:00 First seen: 2025-02-18
MD5: 633c029adc181f8db716f2141401b803 SHA-1: 6cb03c38e947c3bd0c1b58f547710b3f73983aa9 SHA-256: 632e2f6696a172df33f88de81472670eb4bcd6ddb4da6e0dff30de7d614669a0
322 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains multiple indicators of exploitation for CVE-2017-11882, including RTF_EQUATION_EDITOR and CVE_2017_11882_ACTIVATION_RELATED heuristics. The presence of large hex-encoded data blocks within OLE objects, specifically RTF_EXCESSIVE_HEX and RTF_MZ_HEX, strongly suggests the embedding of a PE executable payload. The file's structure and heuristic firings indicate a malicious OLE object designed to trigger the Equation Editor vulnerability for initial execution.

Heuristics 9

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1049KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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://ocsp.verisign.com0
    • http://ocsp.digicert.com0C
    • http://ocsp.digicert.com0A
    • http://ocsp.digicert.com0X
    • http://schemas.microsoft.com/office/word/2003/wordml
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/
    • https://www.verisign.com/rpa
    • http://csc3-2010-crl.verisign.com/CSC3-2010.crl0D
    • https://www.verisign.com/rpa0
    • http://csc3-2010-aia.verisign.com/CSC3-2010.cer0
    • http://cacerts.digicert.com/DigiCertAssuredIDRootCA.crt0E
    • http://crl3.digicert.com/DigiCertAssuredIDRootCA.crl0
    • https://www.verisign.com/cps0*
    • http://logo.verisign.com/vslogo.gif04
    • http://crl.verisign.com/pca3-g5.crl04
    • http://cacerts.digicert.com/DigiCertTrustedRootG4.crt0C
    • http://crl3.digicert.com/DigiCertTrustedRootG4.crl0
    • http://crl3.digicert.com/DigiCertTrustedG4RSA4096SHA256TimeStampingCA.crl0��
    • http://cacerts.digicert.com/DigiCertTrustedG4RSA4096SHA256TimeStampingCA.crt0

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00022ce6.bin
011dd4ac173e90140dfc0d0c68d5774b6f48b6589bc9123bf2a4dac34f8166dd
rtf-objdata-decoded RTF \objdata at offset 0x22CE6 496210 bytes
objdata_01_off001209bc.bin
56684de9a3a82fd5fe392f331efb0aef7d8f1ca301483bc8e8af8263a6e0e72b
rtf-objdata-decoded RTF \objdata at offset 0x1209BC 534490 bytes
rtf_svb_00002c19.zip
d39b64319316e088a3b732b0bbaad03692be6c735566f33d475288af16e459ea
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x2C19 8890 bytes