Malicious PDF — malware analysis report

Static analysis result for SHA-256 31b9dee9df966519…

MALICIOUS

PDF

136.8 KB Created: 2011-09-08 05:03:17 Authoring application: FPDF 1.6
MD5: 9ecdcd88abd88502ad5e351c4ad26740 SHA-1: 4cafc7f6113818aadab1c610adec8ddb7e1ba2d9 SHA-256: 31b9dee9df9665198d6dfe036ed9c4b69302a100c27d6bda8279d4aa8f70afda
108 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV with the signature Pdf.Exploit.Agent-36874. ML classification also strongly indicated maliciousness. The presence of an XFA form and an AcroForm button with an action trigger suggests an attempt to leverage PDF vulnerabilities. While no specific script was extracted, the combination of these factors points to a likely exploit delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 4

  • ClamAV: Pdf.Exploit.Agent-36874 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36874
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • Suspicious extracted artifact info 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_001_off000008ed.bin
f4eedd7066cce69f5d940eaf17c1a221bab372c74de21049a0452b78899d18c5
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x8ED 1407 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).