PDF / .TXT malware analysis — malicious · 7853c333ade641eb

MALICIOUS

PDF / .TXT

4.1 KB

MD5: 77d105fc93cf452f0f363ddcb15811f0 SHA-1: bbe27ed9979f916f6608a93751d2f9f0574b04b3 SHA-256: 7853c333ade641ebeab4a70dcbbe7704c1866c4c7f4183fc99168f809c0841e2

258 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that utilizes a custom Base64 decoder and the `eval()` function to deobfuscate and execute exploit code. This code targets CVE-2008-2992 and includes a URL, http://93.174.93.11/~delmonca/u/load.php, which is likely used to download a secondary payload. The ML classifier also strongly indicated maliciousness.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 9

util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992

PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
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.
eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL

Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
JavaScript action low 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.
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.
Embedded URL info EMBEDDED_URL

One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.

URL http://93.174.93.11/~delmonca/u/load.php

Extracted artifacts 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0013_001.js` `d0ff70c0588b88df44e809027326e1f89b961e3d2d856e40000b8a9e31cb2df2`	pdf-javascript-stream	PDF /JS object 13 at offset 0x368	6309 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
`acroform_b64_00.js` `370a9ddc4bf3fff585f2331803febc9954d844034099502b5005b89baeae60ca`	deobfuscated-js	PDF AcroForm base64 (decompressed) at offset 0x99D	3577 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
`custom_b64_stage_000.js` `85fe71200c33f398824631ccde606ec4fbbce8035fb8611c145accabab2137e1`	deobfuscated-js	custom Base64 decoded JavaScript layer 2 (PDF /JS object 13) at offset 0x95E	2025 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).

Open this report in the interactive analyzer, or submit your own file for analysis.