If you are running version 11.40—nulled or otherwise—your server is extremely vulnerable to this attack. The only protection is to upgrade to a patched, fully-supported version, which is impossible with a nulled license.
"cPanel WHM 11 Final Nulled 40" refers to an illegal, pirated version Cpanel Whm 11 Final Nulled 40
is a search term tied to pirated web hosting software that poses severe security risks to servers and websites. If you are running version 11
Hackers do not distribute nulled software out of charity. Almost all nulled control panels are intentionally bundled with malicious code, including: Cpanel Whm 11 Final Nulled 40