Malicious PDF — malware analysis report

Static analysis result for SHA-256 5164b7bdb2b49dea…

MALICIOUS

PDF

12.4 KB
MD5: 93daa72ffc25a92c7542ab976eca986f SHA-1: 2e167b3991d9f1464d9fcfaa23d5fd7c013a58fb SHA-256: 5164b7bdb2b49dead9187c4fe14ef69ff2769d599135a094daf19887f55a09f6
186 Risk Score

Malware Insights

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

The PDF document contains embedded JavaScript, identified by the 'PDF_JAVASCRIPT' and 'PDF_JS' heuristics. Specifically, the 'CVE_2007_5659' heuristic indicates the exploitation of a known vulnerability related to the 'Collab.collectEmailInfo' function within PDF annotations. This vulnerability is used to execute a JavaScript stager, which is further deobfuscated and recovered as 'annotation_subject_callee_hex_stage_000.js' and 'deobfuscated.js'. The primary function of this stager is to download and execute a second-stage payload, as indicated by the 'PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER' heuristic.

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 3

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
1ea9bacd6ce8e4ca288ae6ea5961faba4e68c505c0e135f1264713c4e25c7b24
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5409 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
ee5ff956ee0645ffde0c63d922ca6692171ffcda6bbabeb7713bdc0f65b85c8e
deobfuscated-js PDF JavaScript deobfuscation pass 74437 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).