PDF malware analysis — malicious · 896fd4620054edb2

MALICIOUS

PDF

73.4 KB

MD5: 1031eb9f1e5ed96ada273311f1931a38 SHA-1: a95057ae4cdc84f98761d2aa25cfdca071b2d019 SHA-256: 896fd4620054edb2563b567efa7c31e58093508d3dac1155050750fb0f9a1367

316 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that is heavily obfuscated using binary-XOR encoding and string manipulation techniques like String.fromCharCode. This script is designed to exploit the CVE-2007-5659 vulnerability via the Collab.collectEmailInfo method. The primary goal appears to be downloading and executing a second-stage payload, as indicated by the 'Pdf.Dropper.Agent' ClamAV signature and the ML classifier's high confidence.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 9

Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659

PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (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.
ClamAV: Pdf.Dropper.Agent-7280064-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Pdf.Dropper.Agent-7280064-0
eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution
Binary-XOR JavaScript stager high PDF_BINARY_XOR_JS_STAGER

PDF JavaScript stores viewer-version payload branches as long binary digit strings, XORs each bit pair, converts 8-bit chunks with String.fromCharCode, and evals the recovered exploit stage.
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.
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 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0004_000.js` `2685615318f73d5fe78492d9cbb85bc12c2b4fc5710f076884b70f243cb5387e`	pdf-javascript-stream	PDF /JS object 4 at offset 0xC0	74842 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
`javascript_obj0004_001.js` `3fc1015dca37653bf14eef1535e3d1aa14355c94a8213b0770b2214db8f6a29a`	pdf-javascript-stream	PDF /JS object 4 at offset 0xE3	74953 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
`binary_xor_stage_000.js` `0a2bbb473d537fbe932163f3f5ef02023e1b0367e1ba39c4bd8a266041f88a89`	deobfuscated-js	binary-XOR decoded JavaScript at offset 0x3D7	1213 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 3 eval/decoder/string-building token(s).

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