PDF malware analysis — malicious · c9fab2ee4b054860

MALICIOUS

PDF

8.0 KB

MD5: 2892c90d619fec3fe4917422e6d99b5b SHA-1: 075750c6ce4c2e1fd999a115631bfe6900d0710a SHA-256: c9fab2ee4b054860c2ef74601d1ea6c3b7632cba8098879fa1634a43e7eea8ca

226 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 JavaScript T1204.001 Malicious Link or Macro: Malicious Link T1071.001 Web Protocols: HTTP

The PDF sample contains obfuscated JavaScript, identified by multiple heuristics including 'PDF_JAVASCRIPT', 'PDF_JS_OBFUSCATED_DROPPER', and 'CVE_2007_5659'. The JavaScript is designed to decode and execute a second-stage payload, likely a downloader. The ML classifier strongly indicates maliciousness, and ClamAV also detected it as 'Pdf.Exploit.Agent-35916'. The primary attack vector appears to be exploiting a known PDF vulnerability to achieve arbitrary code execution.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 8

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)
ClamAV: Pdf.Exploit.Agent-35916 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Pdf.Exploit.Agent-35916
Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER

PDF JavaScript shows 5 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_codec_loop, hex_dashed_payload, incremental_eval_build, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
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)
syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN

PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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.

Extracted artifacts 4

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0005_000.js` `6c41320119e160dc719997b9a2efb3600ea9d7e9d7e44b4dc2125762dc9f365f`	pdf-javascript-stream	PDF /JS object 5 at offset 0x148	505 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_000.js` `84a2deeabf2b2ebf2261263a25da622c9f5a37f54e15677c30b7b236cd61b634`	deobfuscated-js	repeated-marker hex decoded JavaScript at offset 0x1B00	1626 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_001.js` `8d2c238509adc1bdb7ec2e1910f2811a23316d905ac3a6d2a9cb9f276a2da2cb`	deobfuscated-js	annotation-subject callee-key decoded JavaScript at offset 0x355	4962 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 5 eval/decoder/string-building token(s).
`deobfuscated.js` `f253355e9757169f045b9a7a33d9206ca05fe2f101cfafabbbb6acac518ead64`	deobfuscated-js	PDF JavaScript deobfuscation pass	45136 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 7 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.