Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec6b792ad5e64471…

MALICIOUS

PDF

11.9 KB
MD5: 6b89b567a7dea2ab80642713d5bf3dbe SHA-1: a213a8f710fc614f6dd5e0f4b86cb6bc09c4ead7 SHA-256: ec6b792ad5e6447166bf376157f7fc2fafe7351684cc17eae27fa666d04f2769
224 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript 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 exploitation of a known vulnerability (Collab.collectEmailInfo) to execute a JavaScript stager. This stager is further processed and deobfuscated, as evidenced by the extracted files 'annotation_subject_callee_hex_stage_000.js' and 'deobfuscated.js'. The primary function of this stager appears to be downloading and executing a second-stage payload, characteristic of a malicious PDF dropper.

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.
  • Suspicious extracted artifact high 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.
  • 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)

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
09b833b19b776d2e5471ad42302546d0974e1a79dbedfe5ad979240db9cc4eab
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5024 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
30fff04d9d4ac33c9b5d4f057018f806efa12d86e6b0dd617e76c979eae1938e
deobfuscated-js PDF JavaScript deobfuscation pass 76929 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).