Malicious PDF — malware analysis report

Static analysis result for SHA-256 77fefe2f047730e1…

MALICIOUS

PDF

136.8 KB Created: 2011-09-08 05:03:17 Authoring application: FPDF 1.6
MD5: c5b0191f5d93177bbc49ff4a9735d9c2 SHA-1: bfe1fb2aec22aabf50b2bc751ed00a19fb676364 SHA-256: 77fefe2f047730e101179d78c39580ddbb222fdf90a3078193326a1b1cbb9e4e
108 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically identifying it as Pdf.Exploit.Agent-36874. The presence of an XFA form and an AcroForm button with an action trigger suggests an attempt to exploit PDF vulnerabilities. The ML classifier output of 0.999296 further strengthens the confidence in its malicious nature. No scripts were extracted, but the file structure and heuristic firings indicate 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
b306b9074105d1eb9930246946855312a827a4f8a760dca1fc1710bb025884a8
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x8ED 1420 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).