Malicious PDF — malware analysis report

Static analysis result for SHA-256 e22c12eb65451cac…

MALICIOUS

PDF

7.8 KB
MD5: 69cf281e4139b8944099c8254a00e665 SHA-1: 1c6daa132857cd71d2461ee7bcf0aeee2762449c SHA-256: e22c12eb65451cac6ac735f97b4f7a0d75b6a69f05ef5f80d76640a0fee7bbfa
194 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1071.001 Web Protocols

This PDF document exploits CVE-2007-5659, leveraging embedded and obfuscated JavaScript to download and execute a second-stage payload. The critical heuristic 'CVE_2007_5659: Collab.collectEmailInfo' and 'PDF_JS_OBFUSCATED_DROPPER' strongly indicate a dropper functionality. The JavaScript is heavily obfuscated, making detailed analysis of its exact actions difficult, but its purpose is clearly to facilitate further malicious activity.

Heuristics 8

  • 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-35916 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35916
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 5 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_codec_loop, hex_dashed_payload, incremental_eval_build, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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)
  • 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_obj0005_000.js
6c41320119e160dc719997b9a2efb3600ea9d7e9d7e44b4dc2125762dc9f365f
pdf-javascript-stream PDF /JS object 5 at offset 0x148 505 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
e83a87f8e8adbce71d0cf4e2fefcf783f4d2b4c6e221ce83192c9d2624a0e7a5
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1A04 1813 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
138bd057380dfce760aaaf6e485eaecf24f821d07fc74ae284b34362825aae15
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x352 4744 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).
deobfuscated.js
7e1a65b269dabb57c0d85eba19896e0b77d3730b00cba31571a32646ad99aff0
deobfuscated-js PDF JavaScript deobfuscation pass 26520 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).