Malicious PDF — malware analysis report

Static analysis result for SHA-256 478b11bd18b02ff6…

MALICIOUS

PDF

7.9 KB
MD5: aeac7588d45ca6376d9bf912c769229c SHA-1: ab1e15b79fb326b65b72fb8baffe965efeaa080e SHA-256: 478b11bd18b02ff69b4ab84ced01323008dc4215e250763d3c9d54990baabf58
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious Link/URL

This PDF document exploits CVE-2007-5659, leveraging embedded and obfuscated JavaScript to download and execute further stages. The critical heuristic 'CVE_2007_5659: Collab.collectEmailInfo' and 'PDF_JS_OBFUSCATED_DROPPER' strongly indicate a dropper functionality. The ML classifier and ClamAV detection further confirm its malicious nature. The exact payload and download URLs are not directly visible due to obfuscation, but the exploit mechanism is clear.

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.

FilenameKindSourceSize
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
0abb5fb1325dbce4d5e951053129d17852b872e42d3210df936e79901ce60bc0
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1A5C 1819 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
2bc6ade281c6559a9868d817b496b57327ee1b63913b59ab0e35fb66026c7fc1
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x329 4941 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
e7e13e4634a41398cebf60b948c5434057f647f52b94295ca39dee5b39dad4a8
deobfuscated-js PDF JavaScript deobfuscation pass 23065 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).