Malicious PDF — malware analysis report

Static analysis result for SHA-256 a22cfb0fa1c25184…

MALICIOUS

PDF

11.9 KB
MD5: c7a5eb268611b1f047dc306c42fac506 SHA-1: 71d2375105d46989d09154de5ce63a40d9d30c85 SHA-256: a22cfb0fa1c251845e9965405c7c87473eef2b9d1b1d6e08dfa924d00a247da7
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1204.002 Malicious File

The PDF file contains embedded JavaScript, triggered by the CVE-2007-5659 exploit targeting the Collab.collectEmailInfo function. This JavaScript is heavily obfuscated and appears to act as a stager, indicated by the heuristic 'PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER' and the presence of multiple deobfuscated JavaScript files. The ClamAV detection 'Pdf.Exploit.Agent-36063' further confirms its malicious nature. The primary attack vector is the exploitation of a PDF reader vulnerability to execute arbitrary code.

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
f72b25c9c97cc8ab233faa0062253f8544f8e29e050d5aad1a8ea4f3cc9d6d01
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5029 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
c3ffd31b48bf18f68f752999a8c56b3d5b9c23109455f90747f83ecc3fe3f00b
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12101 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
be48a41e336527dc850591452102c98c4c9c783b2e6314af71c5006a65e672d5
deobfuscated-js PDF JavaScript deobfuscation pass 74677 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).