Thinlinc's HTML5 client is a great option to provide zero support RemoteAccess.
Security is a bit week, at least the daemon is running with root and the noVNC client had also some security issues in the past.

Anyway, with fail2ban 0.91 and above you can adapt the multiline patterns you need to do a proper banning of failed logins.

Logfile: /var/log/tlwebaccess.log

Failed Login Pattern:

2015-12-02 09:07:28 INFO tlwebaccess[13758]: Connection from ::ffff:8.7.6.1, port 46540
2015-12-02 09:07:31 ERROR tlwebaccess[13759]: Failed authentication for user u'dfasd'

/etc/fail2ban/jail.local

# set your lans into
ignoreip = 127.0.0.1/8 10.10.0.0/16

destemail = support@domain.com
sender = support@domain.com

# depending on your os filewall 
banaction = ufw

# JAILS
[tlwebaccess]
enabled  = true
port     = 300
filter   = tlwebaccess
logpath  = /var/log/tlwebaccess.log
findtime = 300
bantime  = 36000
maxretry = 3

/etc/fail2ban/filter.d/tlwebaccess.conf

# Fail2Ban configuration file
#
# Author: Chris Ruettimann<chris@bitbull.ch>
#

[Init]
maxlines = 4

[Definition]
_daemon = tlwebaccess

# Option:  failregex
# Notes.:  regex to match the password failures messages in the logfile. The
#          host must be matched by a group named "host". The tag "<HOST>" can
#          be used for standard IP/hostname matching and is only an alias for
#          (?:::f{4,6}:)?(?P<host>[\w\-.^_]+)
# Values:  TEXT
#
failregex = .* Connection from ::.*:<HOST>, .*\n.* ERROR tlwebaccess.\d*.: Failed authentication for user .*

# Option:  ignoreregex
# Notes.:  regex to ignore. If this regex matches, the line is ignored.
# Values:  TEXT
#
ignoreregex =

 

After testing, banning should word like this.

2015-12-02 09:07:24,988 fail2ban.filter         [2166]: INFO    [tlwebaccess] Found 8.7.5.1
2015-12-02 09:07:32,025 fail2ban.filter         [2166]: INFO    [tlwebaccess] Found 8.7.5.1
2015-12-02 09:07:37,048 fail2ban.filter         [2166]: INFO    [tlwebaccess] Found 8.7.5.1
2015-12-02 09:07:37,973 fail2ban.actions        [2166]: NOTICE  [tlwebaccess] Ban 8.7.5.1