Malicious PDF — malware analysis report

Static analysis result for SHA-256 62a00586b4e02b63…

MALICIOUS

PDF

2.9 KB
MD5: 77019cd877faacab2b9c9cfb91d19a0a SHA-1: 8dc142e7665657c5e7077973d57eea9a5018392e SHA-256: 62a00586b4e02b6368f4ad697a5d61323bc453e538b0060f09e6cc47a59752a0
258 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that exploits CVE-2007-5659 in Adobe Reader. The deobfuscated JavaScript contains a URL, http://www.privet3.cn/myexp2/getexe.php?spl=pdf_exp, which is likely used to download and execute a second-stage payload. The ML classifier strongly indicates maliciousness.

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.
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • 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://www.privet3.cn/myexp2/getexe.php?spl=pdf_exp

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0009_000.js
cbf4689f61d5c42471ca8e49ed86ff74c5241f6fd4da1ae902903ccd94beb55b
pdf-javascript-stream PDF /JS object 9 at offset 0xD6 20393 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
generic_stage_recovery_000.js
7683978e701762fa414eeb8b399b3bff11415bd9f8e5fd4601ac9ddbada0acd0
deobfuscated-js generic stage recovery percent-decode from JavaScript object 9 at offset 0xD6 5002 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 10 eval/decoder/string-building token(s).
generic_stage_recovery_001.js
a46b1dab6f68e6d433ded5553113975212c0ffe3ab3c136b98740d23614cc4f0
deobfuscated-js generic stage recovery percent-decode -> percent-decode from JavaScript object 9 at offset 0xD6 4998 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 10 eval/decoder/string-building token(s).