PDF malware analysis — malicious · 1c4617f5c88dd674

MALICIOUS

PDF

15.8 KB

MD5: e70882997b94d755d7e021d75470c4c1 SHA-1: 87c7b4c60489290d68f70a11eb2e37c522b54195 SHA-256: 1c4617f5c88dd67486a6abedca938e0e98e80502b024cfa02e20f7ff28e9faff

96 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell

The PDF contains obfuscated JavaScript, identified as a multi-stage dropper. The heuristics indicate that it reads an annotation subject as an encoded payload and uses a hex-dashed payload, along with anti-analysis checks. The extracted artifacts 'deobfuscated.js' and 'legacy_pdfkit_stage_000.js' are likely components of this dropper, suggesting the file's purpose is to download and execute further malicious content. The ML classifier strongly supports a malicious verdict.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 5

Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER

PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, 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.
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.

Filename	Kind	Source	Size
`javascript_obj0005_000.js` `a3319192cac6d4dc4eeb6af2d736b0ffec979b23116a003bc7c23382761c32a5`	pdf-javascript-stream	PDF /JS object 5 at offset 0x148	733 bytes
`legacy_pdfkit_stage_000.js` `aeac4af7aede4dcde8da06362d2c37cdb257af422c504be2253077dc38fb2496`	deobfuscated-js	repeated-marker hex decoded JavaScript at offset 0x1AFA	12131 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` `1f9b6810a26a7de2d62092c0d6b570ba8fcde341ec5537c0b27996b71c77229a`	deobfuscated-js	PDF JavaScript deobfuscation pass	111827 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 long base64-like blob(s).

Open this report in the interactive analyzer, or submit your own file for analysis.