Malicious PDF — malware analysis report

Static analysis result for SHA-256 897b48f03a1ba73b…

MALICIOUS

PDF

12.1 KB
MD5: fec5c2e6698b7521f961437cb33b4900 SHA-1: 886bbb8a1207ab63ec11abdbe50ceedcaaf7e77f SHA-256: 897b48f03a1ba73b633bff65449ea4aa188fe5bb2c6ae5242be7d4e92e673793
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is heavily obfuscated and appears to be a stager. The critical heuristic 'CVE_2007_5659: Collab.collectEmailInfo' indicates the exploitation of a known PDF vulnerability to execute this JavaScript. The JavaScript is designed to download and execute a second-stage payload, as suggested by the presence of multiple deobfuscated JavaScript files and the 'PDF_JAVASCRIPT' and 'PDF_JS' heuristics. 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
a46819db4b2e165e87f17fd9beff146ee34d1cf6ea23fca9571ce5688edc8678
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5141 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
4804946580c86d167c34c54170c4a847dd0545bc00d2dd09f1548dad419d5a36
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12269 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
5cd76a41d7450c1e37a5d226a4416ebd0a351c9d8afe703a4423deaee56f75da
deobfuscated-js PDF JavaScript deobfuscation pass 80385 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).