Malicious RTF — malware analysis report

Static analysis result for SHA-256 8c2fbd54752a7faa…

MALICIOUS

RTF

5.40 MB Created: 2018-05-27 14:55:00 First seen: 2018-08-05
MD5: a173c835ab88ff6fe8bba3edf4b7fff0 SHA-1: e143443be6a8a34d4e8755c3833ec5073f5db032 SHA-256: 8c2fbd54752a7faa25f7d67dbdf5634cd1700eb0f77fa9d9fa7107e7198d1614
282 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 (Equation Editor) and CVE-2017-8759 (MSXML SAX OLE activation). It also contains excessive hex data and an embedded OLE object, suggesting it is designed to deliver a secondary payload. The embedded URL points to an MSI file, further supporting the payload delivery hypothesis.

Heuristics 8

  • 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.
  • CVE-2026-21514 — Word/OLE security bypass in RTF high CVE likely CVE_2026_21514
    RTF contains a hidden \svb hex package with DrsE2oDoc and downRevStg drawing compatibility parts. This matches an observed CVE-2026-21514 exploitation shape that manipulates Word's internal document structure and trust decisions.
  • \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 ~1777KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \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 https://aboveyarri.com/28b.msi In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off005032b3.bin rtf-objdata-decoded RTF \objdata at offset 0x5032B3 15672 bytes
SHA-256: 07a0b4a9073e1d2eebbbbd05b6e4116409f9d70ad8a20517fe4bc5da5f97dc00
rtf_svb_001b61bd.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x1B61BD 1793 bytes
SHA-256: 4ce1f2ec40c451a919f77224d85d9ff905f9195aa5a0c2445e159deea2b45c10