Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b11f31005b25fbc…

MALICIOUS

PDF

12.2 KB
MD5: ae8fcdd65c4228cfa39f0b656d0dda72 SHA-1: 365caa43a71bb3e6ac9ebcc60d26ef82afc43be6 SHA-256: 7b11f31005b25fbc3e901d4bcc56e89c1fcae77c73d5193bc3ccf8d9cd4acaf4
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, triggered by the CVE-2007-5659 vulnerability using the Collab.collectEmailInfo function. This JavaScript is heavily obfuscated and appears to be a stager, designed to download and execute a second-stage payload. The ClamAV detection further confirms its malicious nature. The exact payload and ultimate goal are not fully discernible due to the obfuscation, but the exploit chain is clear.

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
4aac84360c14ab17f0b0a71b03ae729745f0b344010a70822b7d9a4ae863bf09
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5208 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
12a5b2c7039d335a580145d2c8ce6ce956fbbd1a7789446014f8cbc2c42ae7b4
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12373 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
597b8f20b0c1b4e6ffc65922f24b7b84bcbb819d5da538c4eb116b2b7b0b962b
deobfuscated-js PDF JavaScript deobfuscation pass 75632 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).