Usage ideas
One thing parasite code can do is call clone() and create thread having access to main process VM, FDT, FS, etc. The new thread can then
- Check socket FDs to get stuck/closed by polling them
- Apply "logrotate" on the fly
Another is to do some activity on the victim and then just unload. With this we can
- Death detection. Open pipe/socket and pass the other end outside. Once the victim dies the pipe/socket will wake up.
- Binary updates. E.g. live patching or libr relink
- Inject socket spy -- instead of opened socket create a unix one, put it in place of original one and send the latter back to caller so that any traffic flow in one goes "through" the spy
- Do "nohup" on the fly
- Debug stuff by MSG_PEEK-ing sockets messages of tee+splice sockets
- Re-connect sleeping sockets to other addresses (not 100% safe)