Malicious RTF — malware analysis report

Static analysis result for SHA-256 866a9be2f90b18f5…

MALICIOUS

RTF

3.49 MB Created: 2024-04-03 08:46:00 First seen: 2025-09-19
MD5: 9dfeb7a4c8dee8b7c2977a8b936946b2 SHA-1: 817edcf8613a105683f73c7e4ca19e1701ae82d9 SHA-256: 866a9be2f90b18f54c623063b0c533804aa0eb1217e334b2cb033348422ecdf5
402 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.003 Windows Command Shell T1204.002 Malicious File

The RTF file contains multiple critical heuristic firings indicating exploitation of CVE-2017-11882 (Equation Editor) and CVE-2017-8759 (MSXML SAX OLE activation). These vulnerabilities are commonly used to embed and execute malicious payloads. The presence of PE headers within hex-encoded OLE object data further suggests the embedded content is a secondary executable. The file likely acts as a dropper for further malicious activity.

Heuristics 10

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • 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 ~1431KB 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://www.pdf-tools.com\
    • http://ocsp.entrust.net00
    • http://ocsp.entrust.net05
    • http://schemas.microsoft.com/office/word/2003/wordml
    • http://www.adobe.com/go/security-and-compliance
    • https://acrobat.adobe.com/us/en/
    • http://www.pdf-tools.com
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#
    • http://ns.adobe.com/pdf/1.3/
    • http://crl.entrust.net/g2ca.crl0
    • http://www.entrust.net/rpa0
    • http://aia.entrust.net/ovcs1-chain256.cer01
    • http://crl.entrust.net/ovcs1.crl0J
    • https://www.globalsign.com/repository/0
    • http://ocsp.globalsign.com/ca/gstsacasha384g40C
    • http://secure.globalsign.com/cacert/gstsacasha384g4.crt0
    • http://crl.globalsign.com/ca/gstsacasha384g4.crl0
    • http://ocsp2.globalsign.com/rootr606
    • http://crl.globalsign.com/root-r6.crl0G

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00003a12.bin
35276d71d9997b6bd1057e45dc2e11de6d507ce96a3c692af2c3b5eaacc872ab		 rtf-objdata-decoded RTF \objdata at offset 0x3A12 728714 bytes
objdata_01_off00172f58.bin
e1f3559241a80335443d4d0c1964ccd8e69099cdcc0985e3ea0b86b89e746883		 rtf-objdata-decoded RTF \objdata at offset 0x172F58 584546 bytes

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