Ysoserial-0.0.4-all.jar is a specific version of the ysoserial library, which includes various payloads and gadgets for exploiting serialization vulnerabilities. This version, in particular, provides several exploit payloads, including:
java -jar ysoserial-0.0.4-all.jar -t CommonsCollections2 -c "touch /tmp/ysoserial_test" -f java ysoserial-0.0.4-all.jar download
The official version of ysoserial does not typically release a pre-compiled 0.0.4-all.jar through standard package managers. You must obtain it from the source or build it yourself. Ysoserial-0
Note: As this is a penetration testing tool, it is commonly flagged by antivirus software. Use it only in authorized, educational, or controlled testing environments. provides several exploit payloads