Simple CDHack Detection.

#include <amxmodx>

new bool: g_HasCheat[33]
new bool: use_amxbans

public plugin_init( ) {
    register_plugin( "AntiCDHack", "1.0", "h010c" )
    new amxbans = get_cvar_pointer("amxbans_version")
    if ( !amxbans )
        use_amxbans = false
    else
        use_amxbans = true
}

public send_cvar(id)
    client_cmd(id-1234, "cd_version")

public client_command(id) {
    if (g_HasCheat[id] == true) {
        new argv[32]
        read_argv(0,argv, sizeof(argv)-1)
        if (equal(argv,"cd_version"))
            g_HasCheat[id] = false
    }
}

public client_putinserver(id) {
    if (!is_user_bot(id)) {
        g_HasCheat[id] = true
        set_task(5.0,"send_cvar",id+1234,_,0,"a",5)
        set_task(60.0,"CheckCheat",id)
    }
}

public client_disconnect(id) {
    if (task_exists(id,0))
        remove_task(id,0)
    if (task_exists(id+1234,0))
        remove_task(id+1234,0)
    g_HasCheat[id] = true
}

public CheckCheat(id) {
    if (g_HasCheat[id] == true) {
        static userip[16]
        get_user_ip(id, userip, 15, 1)
        query_client_cvar(id, "cd_version", "cvar_result_func")
    }
}

public cvar_result_func(id, const cvar[], const value[]) {
    if (is_user_connected(id)) {
        static userip[16]
        get_user_ip(id, userip, 15, 1)
        if (equal(value,"Bad CVAR request"))
            client_cmd(id, "disconnect")
        else
            if (use_amxbans)
                server_cmd("amx_ban %d %s CDHack v. %s Detected", 0, userip, value)
            else {
                server_cmd("kick #%d ^"CDHack v. %s Detected^"", get_user_userid(id),value)
                server_cmd("addip %d %s",0,userip)
            }
    }
}