PDF malware analysis — malicious · 4b865366977fcacf

MALICIOUS

PDF

33.5 KB

MD5: ff32bb10a328c1d608d712ddac047227 SHA-1: 27c8d1f616a43d7508fe76d3e57a9afdd3c7bc55 SHA-256: 4b865366977fcacf183aa9993139dcd4a95e185bda1d50d7c2edd69f07eaaae4

190 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains XFA (XML Forms Architecture) data, which is known to be a vector for exploits. Specifically, the 'PDF_XFA_HEAP_SPRAY' heuristic indicates the presence of heap spray exploit code within a decoded stream. This suggests the document is designed to leverage a vulnerability in PDF rendering engines to execute malicious code. The embedded JavaScript file, 'stream_000_off00000061.js', likely contains the second-stage payload or further obfuscated exploit logic. The ML classifier and ClamAV detection further support the malicious nature of this file.

Machine Learning

Nyx PDF Classifier malicious score 0.9790

Heuristics 7

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: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION

ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
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)
PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED

The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PSSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
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.

Filename	Kind	Source	Size
`stream_000_off00000061.js` `d7a8452d94f15991cbddc049f1d9476f37ec1cd67a18d240e17c68cb3c3a7993`	decompressed-pdf-stream	PDF FlateDecoded stream at offset 0x61	84648 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s).

Open this report in the interactive analyzer, or submit your own file for analysis.