Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee44126b4a79b34d…

MALICIOUS

PDF

12.1 KB
MD5: afd4f182cf55f6baf01603d9acb2723c SHA-1: 60f873a81f8ab52f4097effb8234a33a3d1c9ad1 SHA-256: ee44126b4a79b34d50424835da96465523f44e334f98ca93280a198303cde5fd
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically leveraging the CVE-2007-5659 vulnerability through the `collab.collectEmailInfo` function. This JavaScript is heavily obfuscated and appears to act as a stager, indicated by the presence of multiple deobfuscated JavaScript files. The primary function of this script is to download and execute a second-stage payload, although the exact nature of the payload cannot be determined from the provided evidence. The ClamAV detection further confirms the malicious nature of the file.

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
b4e2f2c23fa1bb465849f46044e1999f7330085ed003511e5dd4809713c6ea9f
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5127 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
cabb0fdf830e48a8aa35f12a9a98fc534e1fe4123b5231fa84558e730265a027
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12219 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
0044a638b992f7baee311243d395e89836b5fa7593458c25449e5d05d22ffbc4
deobfuscated-js PDF JavaScript deobfuscation pass 77488 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).