Malicious RTF — malware analysis report

Static analysis result for SHA-256 c63ccc5c08c3863d…

MALICIOUS

RTF

50.2 KB Created: 2017-11-18 21:52:00 First seen: 2020-01-07
MD5: 89e36574ece95178c511705a999a4e6e SHA-1: 4e8a4773ef0c9ff74b8091020ca4b66dc8c020ea SHA-256: c63ccc5c08c3863d7eb330b69f96c1bcf1e031201721754132a4c4d0baff36f8
342 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object specifically identified as Microsoft Equation Editor, triggering critical heuristics related to CVE-2017-11882. This indicates the file is designed to exploit this known vulnerability for client-side code execution. The presence of shellcode strings within the decoded object further supports this conclusion. The likely delivery vector is spearphishing attachment.

Heuristics 9

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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.
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • Equation Editor object class critical RTF_OBJCLASS_EQUATION
    Object class 'equation.3' references Equation Editor
  • \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.
  • 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 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 http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002e8d.bin rtf-objdata-decoded RTF \objdata at offset 0x2E8D 3494 bytes
SHA-256: aa18d69e81918378350006dcc3acb7901345aa7265aa621edbc4a381d00c3bee
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): cmd.exe /ccalc.exe & AAAAAAAAAAAAAAAAAAAAAAA C

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