Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b53be1ad59070c6…

MALICIOUS

PDF

9.4 KB
MD5: 58df9501b2c98ac44ad8e526f0c85806 SHA-1: f629e0cd8168c8ef05d182aef0e0f86f2d3b4a5f SHA-256: 4b53be1ad59070c604c97a2d2629c7d8ec5775f376f8f64d2051210ebe0cd347
126 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF sample contains embedded JavaScript, triggered by the CVE-2007-5659 vulnerability via the 'collab.collectEmailInfo' function. This JavaScript is heavily obfuscated and acts as a stager, decoding and executing a larger payload. The analysis recovered two deobfuscated JavaScript files, indicating a multi-stage execution process designed to deliver a malicious payload.

Heuristics 6

  • 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)
  • 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
dc37160715dd481d0bf49e7af5079aad16ed0e66896c1ae05ca27000b3e4454e
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 259 bytes
annotation_subject_callee_hex_stage_000.js
a1d659bee536ff4e3342611178f2eb4345e8b9bcf1dae6a344845e94f32bcf75
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5023 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
abc925062537203f92e582e14fbbed280f0d28a6b68217fee33ae60daabc3286
deobfuscated-js PDF JavaScript deobfuscation pass 45056 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).