Malicious PDF — malware analysis report

Static analysis result for SHA-256 94fdcedfffb602ae…

MALICIOUS

PDF

43.1 KB
MD5: f944201e939e9fd5d1eddf0794ab8b66 SHA-1: 87cec4d767a604edc24bd3ca7041fab88001ba05 SHA-256: 94fdcedfffb602ae0bae2de01159ed7c16fca8d02cac39901e902464655dac36
168 Risk Score

Malware Insights

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

The PDF file contains XFA (XML Forms Architecture) which is known to be vulnerable to heap spray attacks. The embedded JavaScript, identified by the PDF_XFA_HEAP_SPRAY and PDF_XFA_SCRIPT heuristics, is responsible for executing this exploit. The script likely downloads and executes a second-stage payload from the reconstructed URL: http://rotbirakohashan.no-ip.info:80/eHYnGtg?dcQ H=13&zWsL=12651. The ML classifier also strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9880

Heuristics 6

  • 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.
  • 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_off00000bfd.js
5427ab1011ef927197185237a48076b7974886ae246c530ee2c0bf69760a583d
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xBFD 449256 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).