Malicious PDF — malware analysis report

Static analysis result for SHA-256 897fe17ee6844db3…

MALICIOUS

PDF

9.5 KB
MD5: bd9659fb899eea6a6c5df31d0de1be39 SHA-1: b61b3ca859ae8d17fc41e7dfb374802b6765b0bc SHA-256: 897fe17ee6844db3abb9639b84e99f7f5abf6b7ca1a5982e6e7d64c372521ddd
266 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1027 Obfuscated Files or Information

This PDF file exploits CVE-2007-5659 using a JavaScript stager embedded within an annotation subject. The stager utilizes eval() and unescape() functions, indicating obfuscation, and ultimately decodes and executes a larger JavaScript payload. The presence of multiple deobfuscated JavaScript files and the critical ClamAV detection (Pdf.Exploit.Agent-35912) strongly suggest malicious intent, likely to download and execute a second-stage payload.

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)
  • ClamAV: Pdf.Exploit.Agent-35912 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35912
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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
7218a1c68060953321573daa035b16f5f32928ce25a9eb656690dbe78cd9464e
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 201 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
4e366bc87062851754fc05c3e4e091a77ac0938a260453cde5415f733d2cdf1d
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5157 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
e728a5ce0e1b0b083ac8ee01f9ce3d2a88c1cfe1c426b9a4896d4ddabe49f9a9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2B5 12192 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
5cefa8875a74ba14dcd031757affe829bc8640dc368de09e85ec0bebe79b24e6
deobfuscated-js PDF JavaScript deobfuscation pass 67806 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).