Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fdb68535715b43a…

MALICIOUS

PDF

12.0 KB
MD5: acbbd0efaa5961dac9e228a94a69c7ad SHA-1: b3f6f633cc3fd1bfdd7ad48607800e2f2d513cf0 SHA-256: 8fdb68535715b43a55b01692c1bce191c149a551551aa8f3ab6b677b303c5bd2
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, indicates the use of a specific exploit technique involving annotation subjects to stage and execute JavaScript. The ClamAV detection of 'Pdf.Exploit.Agent-36063' further confirms its malicious nature. The embedded JavaScript is heavily obfuscated but appears to be designed to download and execute a second-stage payload.

Heuristics 7

  • 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-36063 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36063
  • Annotation subject callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • 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_obj0007_000.js
eb39e2de4dbbc100de6d3e30aa43ff78fa075618862ba1ebba5151ea3a3b848d
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 273 bytes
annotation_subject_callee_hex_stage_000.js
86631e888fd166c650b7cb6b09b8f1b49830dbc3fa1daa7fef71435933094d9b
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5094 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
3951ae1f66cc75a8c26996e8349b98df615bb1c560cf5955486d3a1342b7d47f
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12194 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
20fb72002c809622428a9882c97ce61de5d32703ce4fd287b455dbf1dee09e8f
deobfuscated-js PDF JavaScript deobfuscation pass 77641 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).