Malicious RTF — malware analysis report

Static analysis result for SHA-256 a53a13a6f3aed852…

MALICIOUS

RTF

8.82 MB Authoring application: LibreOffice/5.3.7.2$Linux_X86_64 LibreOffice_project/6b8ed514a9f8b44d37a1b96673cbbdd077e24059 First seen: 2018-03-30
MD5: e2c5e12034bc1532bb9e6f3393590aed SHA-1: 7feb3f502e9f5573390ce9911b5437ace7bcd795 SHA-256: a53a13a6f3aed8523710ff38a8d38f5aa9ebd9b44a25cc4967130f238f9990a3
522 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains multiple indicators of exploitation for CVE-2017-8570, including Composite Moniker and embedded OLE objects with PE headers. This vulnerability is known to drop and execute SCT scripts. The ClamAV detection 'Xml.Malware.Squiblydoo-6728833-0' further confirms malicious intent, suggesting the embedded artifact is a payload. The document body content appears to be legitimate research material, indicating the exploit is likely the primary malicious component.

Heuristics 12

  • 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: Xml.Malware.Squiblydoo-6728833-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xml.Malware.Squiblydoo-6728833-0
  • 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
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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.
  • Package object class high RTF_OBJCLASS_PACKAGE
    OLE Package object — can wrap arbitrary files
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~4368KB of hex-encoded data inside \objdata sections — may hide a payload
  • Suspicious extracted artifact high 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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 3 \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://www.rand.org/pubs/research_reports/RR1708.html In RTF body
    • https://www.rand.org/In RTF body
    • http://www.rand.org/t/RR1708In RTF body
    • http://www.rand.org/pubs/permissionsIn RTF body
    • http://www.rand.org/giving/contributeIn RTF body
    • http://www.rand.org/In RTF body
    • http://www.rand.org/nsrd/ndri/centers/intel.htmlIn RTF body
    • http://www.rand.org/pubs/research_reports/RR893.htmlIn RTF body

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off007dee4d.bin rtf-objdata-decoded RTF \objdata at offset 0x7DEE4D 494859 bytes
SHA-256: 82dbca9ed1ad8dfe95186052f569ad2f65bb36aadc3ffc887e1fa21097c1791f
objdata_01_off008d08a2.bin rtf-objdata-decoded RTF \objdata at offset 0x8D08A2 713 bytes
SHA-256: fa94950135d6b75a1f46714636b32a953118ac8f69ec9539efbe77596304aac2
Detection
ClamAV: Xml.Malware.Squiblydoo-6728833-0
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell").Run("cmd /c %tmp%\\mico-audio.exe",0,false);
objdata_02_off008d0e83.bin rtf-objdata-decoded RTF \objdata at offset 0x8D0E83 2633 bytes
SHA-256: 48453afbd07e8189a2f4382c993bb123591e02218e73d7a59c5aee32ca4d3d46

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