Malicious PDF — malware analysis report

Static analysis result for SHA-256 be92c6f717df5fae…

MALICIOUS

PDF

11.6 KB
MD5: da7a7ec18dd95ee4465852155f082d3e SHA-1: 87b72c2588507270cbe6bd787316cbe04610bc71 SHA-256: be92c6f717df5fae8608e7763384c880d41656cbfb225f94dd08ac2a76f9e4ec
186 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, identified by multiple heuristics including 'PDF_JAVASCRIPT' and 'PDF_JS'. The critical 'CVE_2007_5659' heuristic indicates the exploitation of a known vulnerability (Collab.collectEmailInfo) to execute a hex-decoded JavaScript stager. This stager is responsible for downloading and executing a second-stage payload. The ClamAV detection further confirms its malicious nature.

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
07d8bc8f762d42ec2e0d7d3dfc8360dd3bcd1531f407b489cd99774d7c896c88
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5024 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
2b6c9bbf88b20d09690671e3fb8fb6b4fa9840a5c603466201f333de0c7769c0
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 11962 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
765b59e9c69d65ddf289aa8dd1db3eb4d0c63a034b8cd1aadf8b5fb450da42cf
deobfuscated-js PDF JavaScript deobfuscation pass 76588 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).