Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3b637d3c97d5d02…

MALICIOUS

PDF

1.95 MB
MD5: efe002d38f6a31ee3b62fd5e0374bad0 SHA-1: 252c652f318f975c33958059beb321264c5c6ec4 SHA-256: d3b637d3c97d5d02359d8eb085b3b71255b31399459f25f63f18a472a6d82ca4
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF file was flagged by a machine learning classifier as malicious with a high probability. Static analysis revealed an embedded JavaScript payload within a PDF stream, indicated by the PDF_EMBEDDED_SCRIPT_PAYLOAD heuristic. This script, named stream_000_off000003b6.js, is likely responsible for downloading and executing a second-stage payload, contributing to the overall malicious nature of the document. The presence of XFA form elements also suggests a potentially complex document structure often used to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 3

  • 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
  • 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_off000003b6.js
f4f680551cd4e6d199e3d466ac7188769dfd80c649771e6d24273104e0fab83b
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3B6 26344 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).