Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca2986d4e9a51355…

MALICIOUS

PDF

15.2 KB
MD5: 7247cd7c2a0e32fd293a0162b5314283 SHA-1: b4acf33879a6fc509a383b0fbbdb34cddd07cc14 SHA-256: ca2986d4e9a513559ee232c3f7efdb992b04641ff233256375fb5d8c1416c102
66 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 this script is designed to download and execute a second-stage payload. The presence of multiple deobfuscated JavaScript files suggests a complex, multi-stage infection chain. The exact download URL and execution details could not be fully reconstructed due to the obfuscation.

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.

FilenameKindSourceSize
javascript_obj0005_000.js
a3319192cac6d4dc4eeb6af2d736b0ffec979b23116a003bc7c23382761c32a5
pdf-javascript-stream PDF /JS object 5 at offset 0x148 733 bytes
legacy_pdfkit_stage_000.js
023c77583fe3bda823d883d9fcb5fadd406ea4b0fca3ffabbdaa1530df48385d
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x19ED 12008 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
6a414ac934b6eb3f29f0eb60ae112953c4c6fc170e5ff6d3505e249fa5db933e
deobfuscated-js PDF JavaScript deobfuscation pass 59048 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).