[NBLUG/talk] Am I under attack?

[Roger House]

By chance I noticed that the file .xsession-errors.old in my home directory
(I'm running Ubuntu 12.04) was more than a gigabyte in size.  A few 
grep's on
the file produced lines like these

     28/01/2015 06:27:07 AM rfbAuthPasswordChecked: password check failed
     debconf: DbDriver "passwords" warning: could not open 
/var/cache/debconf/passwords.dat: Permission denied

There were other ominous looking messages which I can't reproduce at the
moment because apparently each time my system comes up, the current
.xsession-errors.old is deleted, .xsession-errors is renamed to 
.xsession-errors.old,
and a new .xsession-errors is started.  Anyway, there were thousands of 
lines
like the two above, plus others.

Actually, now that I have brought my system up again, here is a sample 
of what appears
in .xsession-errors almost immediately:

** (vino-server:2183): WARNING **: Deferring authentication of 
'74.208.225.179' for 5 seconds
** (vino-server:2183): WARNING **: VNC authentication failure from 
'74.208.225.179'
28/01/2015 06:03:14 AM rfbAuthPasswordChecked: password check failed
28/01/2015 06:03:53 AM [IPv4] Got connection from client 
static-164-148-4-96.hardin.tn.ena.net
28/01/2015 06:03:53 AM   other clients:
28/01/2015 06:03:53 AM      74.208.225.179
28/01/2015 06:03:53 AM Client Protocol Version 3.3

Do these indicate attempts to break into my system?

A recent change to my system:  Last week I installed apache in order to 
do local web
development.  Can this have led to the above messages?  I am new to 
apache so I'm
wondering if there are config files which I need to edit to prevent 
successful attacks.

Any info will be appreciated.

Roger House