What is this strange error in the Apache server logs?

Question

Apache HTTP Server

I'm looking through the Apache server error logs and found a very strange error that I've never seen before:
[Wed Jan 29 11:38:05.420588 2014] [core:error] [pid 4500] [client 86.57.255.92:20043] AH00126: Invalid URI in request \xa3{(i\xc0\xb2hy\xa4\x84\xba\bq/\b7\x0c\xfcV\xbe
What can this error mean? How can I fix it?

Answer 1

here are similar errors in Google, they write that bots are breaking down looking for vulnerabilities