logs show massive spam of "proxy.php" access (1 reply)

Hello,

since I have installed nxginx on my Ubuntu LTS, I see the logs absolutely full of text like this:

2013/07/16 11:07:43 [error] 24590#0: *445 rewrite or internal redirection cycle while internally redirecting to "/index.php", client: 91.237.249.99, server: www.[my host name].com, request: "POST http://50.56.191.147/~cashcorp/proxies/engine.php HTTP/1.0", host: "50.56.191.147", referrer: "http://50.56.191.147/~cashcorp/proxies/engine.php"

2013/07/16 11:09:23 [error] 24590#0: *449 rewrite or internal redirection cycle
while internally redirecting to "/index.php", client: 89.69.13.95, server: www.[my host name].com, request: "POST http://discountbaby63.ru/proxyc/engine.php HTTP/1.0", host: "discountbaby63.ru", referrer: "http://discountbaby63.ru/proxyc/engine.php"

2013/07/16 11:10:29 [error] 24590#0: *453 rewrite or internal redirection cycle while internally redirecting to "/index.php", client: 142.4.98.163, server: www.fleurworld.com, request: "POST http://spamstats.net/proxyc/engine.php HTTP/1.0", host: "spamstats.net", referrer: "http://spamstats.net/proxyc/engine.php"


Is this an issue due to mis-configuration? Are they hackers? Are they succeeding at their hacking?