Malicious PDF — malware analysis report

Static analysis result for SHA-256 f2081bfdb23fe610…

MALICIOUS

PDF

9.5 KB
MD5: 613d1d23b1529de2535a62bfd3799b4b SHA-1: dab2028ecfcaa179f8fadb0b2fb2854b5ad5de08 SHA-256: f2081bfdb23fe6104186625a81103c16cd2f2db48e169a9669a34c0bf6b01dbb
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, indicates the use of a known vulnerability (Collab.collectEmailInfo) to execute a JavaScript stager. This stager is heavily obfuscated and likely downloads and executes a second-stage payload. The presence of deobfuscated JavaScript files further supports this analysis.

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: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
11b03694c4e705ab29873cc5e2c55342ee498b376ac2dc5f05ce17018ef44c38
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 264 bytes
annotation_subject_callee_hex_stage_000.js
ae7bfd477ea582e8d701a7698e8f2bd1fddac25896ee53f8d4a3bffecd911a79
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5109 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
b17308690ec991f6bfcd8e8d128d8c3eb2ddbc16ab55a0c47b0a25e703a5502e
deobfuscated-js PDF JavaScript deobfuscation pass 71092 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).