Malicious PDF — malware analysis report

Static analysis result for SHA-256 433d6978d7c6564f…

MALICIOUS

PDF

395.1 KB
MD5: 260f17f953365b9c460cc58a631428a1 SHA-1: f07e78a11d0b141d084f79b7f7432dbf5f63c376 SHA-256: 433d6978d7c6564fe20da8c2734b7c81547a0b4f7802926e65070e29568047f7
228 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File: Malicious File

The PDF file contains XFA form elements with embedded JavaScript, triggering critical heuristics for XFA heap spray and embedded script payloads. ClamAV identified the file as Pdf.Dropper.Agent-7255079-0. The embedded JavaScript is likely responsible for executing a second-stage payload, although its exact function is obscured by obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • XFA JavaScript heap-spray exploit code critical PDF_XFA_HEAP_SPRAY
    PDF contains XFA script content with heap-spray or shellcode-like JavaScript markers such as large encoded word sequences, util.pack, large arrays, or spray variable names. This is a weaponised Adobe Reader exploit pattern, not a normal interactive form.
  • ClamAV: Pdf.Dropper.Agent-7255079-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7255079-0
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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_000_off00000049.js
0372351f0cb4c23e2ed02ac76db367f727b4464fc4d8fed4166853716cbd9c4f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x49 4194304 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).