Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe4daf2c4950e82c…

MALICIOUS

PDF

136.8 KB Created: 2011-09-08 05:03:17 Authoring application: FPDF 1.6
MD5: 076a1c064b5282a174cdb6ae0b4a34e5 SHA-1: 4c3ee71f56f4a2d8d2046679c9a43dc3c5120315 SHA-256: fe4daf2c4950e82c2701a8ebc4f5829b431474c613fc9a5cb4c66c0c8cfce8c4
108 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by ML classification and ClamAV, with the ClamAV signature indicating it's likely an exploit. The presence of an XFA form and an AcroForm button with an action trigger suggests an attempt to exploit PDF vulnerabilities. The embedded artifact, a decompressed PDF stream, likely contains the exploit code. The document body is heavily obfuscated and does not provide clear user-facing content, reinforcing the exploit-driven nature of the attack.

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
7ca987fc1a7ae750eacb346fa96b3743c92080d1d7bc66b713d30ca0a6d98f28
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x8ED 1490 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).