Malicious PDF — malware analysis report

Static analysis result for SHA-256 8152a2d0cf92a804…

MALICIOUS

PDF

12.8 KB
MD5: 98696f89e63a8465033233fd535d4ae1 SHA-1: 9001c9315a47293c42a98910db3c22f2c57f9795 SHA-256: 8152a2d0cf92a804af57454d0c866ffcb5ddd3361dd21b0e773b4f57d7cf3779
198 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Scripting: JavaScript T1204.002 Malicious File: Malicious JavaScript

The PDF file contains embedded JavaScript that leverages CVE-2007-5659 (Collab.collectEmailInfo) to decode and execute a stager. This stager, identified as legacy_pdfkit_stage_000.js, is designed to download and execute a further payload, indicated by the presence of legacy_pdfkit_stage_001.js. ClamAV also detected this as Pdf.Exploit.Agent-36064, confirming its malicious nature.

Heuristics 6

  • 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)
  • Annotation subject percent-decoding eval stager critical PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER
    OpenAction JavaScript forces annotation enumeration, reads an annotation /Subject payload with getAnnots(), rewrites marker bytes into percent escapes, decodes it with unescape(), and dispatches it through eval. This is a high-confidence exploit-kit staging pattern. It is intentionally not mapped to CVE-2009-1492 unless getAnnots() itself carries the crafted integer or long argument shape for that vulnerability.
  • ClamAV: Pdf.Exploit.Agent-36064 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36064
  • 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.
  • 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.

FilenameKindSourceSize
javascript_obj0007_000.js
a5c8f0f722df4dd9876a0087e1eee65bd3020c5995f94f6729f7e17f3f3677a0
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 331 bytes
legacy_pdfkit_stage_000.js
19f3c00af5d35ed656a3a9415d4972df5c10743b4af52d6f490738ef0dfa4428
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F2 11895 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
1b2ba26f9aa915063270dbf452871d4f20487d293d3e7218b6554f0c7530f8e4
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F2 4930 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).