Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc50349099657f37…

MALICIOUS

PDF

33.5 KB
MD5: 1b21d2962d603dd22975aa1fa8054f33 SHA-1: a486348dbf1f1a96a54392e9818e4a7dc3c69cb1 SHA-256: dc50349099657f37eb44908b7761455ee8a178c5964c13854b90e93f79cb8f11
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell T1566.002 Phishing: Spearphishing with Attachment T1204.002 Malicious File Execution: User Execution

The PDF file contains XFA (XML Forms Architecture) content, 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 an XFA JavaScript stream. This technique is often used to bypass security measures and deliver a secondary payload. The 'CLAMAV_DETECTION' heuristic further confirms the malicious nature of the file. The presence of an embedded JavaScript file, 'stream_000_off00000069.js', suggests that the XFA exploit likely targets this script for execution, potentially leading to further malicious activity.

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.

FilenameKindSourceSize
stream_000_off00000069.js
982ea91feafbdb85530ecfb9d605caa5f77b05cbfcc97b250d19a21526ff28df
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x69 84756 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).