Malicious PDF — malware analysis report

Static analysis result for SHA-256 a46dcfa13fe53e45…

MALICIOUS

PDF

11.7 KB
MD5: 53618598ba5510ca0020b15229a9f5fc SHA-1: 199bb18072af02627c98838a2546dd0e29f26eee SHA-256: a46dcfa13fe53e45706124f9ff01faf309c4d30cef769fb960a134a29f145a2a
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically a stager that utilizes a hex decoder and the `callee.toString()` method to obfuscate malicious code. This stager is triggered by the CVE-2007-5659 vulnerability, specifically the `Collab.collectEmailInfo` function. The primary intent appears to be the execution of a second-stage payload via the decoded JavaScript. The presence of ClamAV detection further supports 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-36088 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36088
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
9fd87306e37a04c361ea1b68a1cf4474b7a018e2270929a8c382cd129d8fc406
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 566 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
6be978708edbbc4d2e92663e4629f5153e596ed57e6313c0e454f717326008b3
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5088 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).