PDF malware analysis — malicious · 471fc073a4cb8cf1

MALICIOUS

PDF

7.8 KB

MD5: 9df83fcf7ca617c54added1912795df9 SHA-1: 6d142de208258058ae20ebd6d7120e0a6aa0eb92 SHA-256: 471fc073a4cb8cf1e752b3cca48885f2f1de5f8149aa1a78fa68df3febee326e

256 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.001 Malicious Link T1071.001 Web Protocols

The PDF file contains obfuscated JavaScript that leverages the CVE-2007-5659 vulnerability via the `collab.collectEmailInfo` function. The script is designed as a multi-stage dropper, indicated by the `PDF_JS_OBFUSCATED_DROPPER` heuristic and the presence of multiple deobfuscated JavaScript files. The primary goal appears to be downloading and executing a second-stage payload, as suggested by the dropper nature of the script and the ML classifier's high confidence score. The `syncAnnotScan` primitive is used to stage the annotation payload, and anti-analysis checks like `app.plugIns.length` are present.

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-36086 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
unescape() call high PDF_UNESCAPE

unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER

PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, 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.
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_obj0006_000.js` `f9b4659beaf681d266cfb5046d495e7b144d406eff72e71ecd4d1451ae25ca11`	pdf-javascript-stream	PDF /JS object 6 at offset 0x143	481 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_000.js` `3960f6e5166874788342d2b6810a5d647d4ff456f43218d545c3c1aa15af1500`	deobfuscated-js	repeated-marker hex decoded JavaScript at offset 0x1A48	1660 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` `afb3523f03a90beed30097f7831a2c308370ea0c71e318eff4f765f061dfd833`	deobfuscated-js	annotation-subject callee-key decoded JavaScript at offset 0x329	4882 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 5 eval/decoder/string-building token(s).
`deobfuscated.js` `fe3dc76b092fd98c061a7cfa1c659203c951a2c924db51a9e200fd216f148dda`	deobfuscated-js	PDF JavaScript deobfuscation pass	22530 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s).

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