Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e385a17bdde57c0…

MALICIOUS

PDF

8.4 KB
MD5: 835cf431bc5f8ebeb08acd4c72187a37 SHA-1: 4ae88b0dac24c97910fbf3e6889657f1d2d12670 SHA-256: 9e385a17bdde57c03f339fde98051e6d92d3f4e73c6a50564922108391a26d8b
138 Risk Score

Malware Insights

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

The PDF sample contains XFA form elements with embedded JavaScript, identified as a heap-spray exploit. This script is designed to download and execute a second-stage payload from the reconstructed URL 'http://dieselhic koryomtoile.com:8382/oshPbY?expid=4&fid=5'. The presence of XFA heap-spray and embedded script strongly indicates a malicious intent to compromise the user's system.

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_off00000a4d.js
99bd1d0b89be4f2ce12106bd93d4791ef3a8fe05401aa7e0449090699cf5eeb0
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xA4D 100140 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).