Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9a4d22b7f2f1a3b…

MALICIOUS

PDF

12.1 KB
MD5: e1de141b2c231305b1e8b1ca26721d23 SHA-1: ad14aeaee137dbdf587fdc77a406bbbb1d4798c7 SHA-256: c9a4d22b7f2f1a3b3f0ef3bfd680096c11c3eed81e9fb978409208dd8430ec9d
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically leveraging the CVE-2007-5659 vulnerability through the Collab.collectEmailInfo method. This indicates an attempt to execute arbitrary code. The embedded JavaScript is heavily obfuscated but appears to be a stager designed to download and execute a second-stage payload. The ClamAV detection of Pdf.Exploit.Agent-36063 further confirms the malicious nature of the file.

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 4

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
a2c5b27bc094507d3368f133da746713486767619dbaecdfdc71418fc4a05811
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5242 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
c825c5798bbaaa8053b34fad456b2ea2375b9019e31b432d10252bd5b694eda2
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12451 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
37317a11a49c1afde3c002d1c3c92c2a234940d7839d27847f46a5b7b82c76d2
deobfuscated-js PDF JavaScript deobfuscation pass 79220 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).