Don't know if you knew this and don't know whether you are interested either, but
by doing a whois lookup of the DNS server address you have listed above (188.8.131.52)
returns the web hosting company Dyynamic Network Services Inc.
You might find it interesting to know that this is the same website which at one time was
hosting Wikileaks until they started getting belted with Denial of service attacks and therefore
promptly let go Wikileaks so as not to jeopardise other client relations.
In relation to your question about the Sendori thing, no I have not witnessed it
or even heard of it for that matter before coming across your thread. CNet and Brothersoft
have it listed as an anti-malware application which is actually supposed to help speed
up (if you believe that) navigation to a desired website. Why or how this product is changing your DNS address if in fact that is the root of your problem in the first place is a mystery.
If the Sendori software is in fact legitimate (and remember that there are products out there claiming
they will help when in fact they are malicious themselves) and if you trust the opinion
of CNet and such sites then Sendori may have had a report from someone affected by the site
you were trying to access effectively blocking it until you manually allowed it into a trusted sites list.
Again, if the Sentori product is legit I would be looking for another root cause
of the changing DNS address problem even though as you say after uninstalling it is OK.
FYI - the most common places to check for Malware or Virus manually are:
1) Through Task Manager -> Processes and Dr. Google to research the processes that may be running/ listed
2) I also like to check the Run and Run Once registry entries in both HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE
You can find what is in those entries by using the following path/s:
HKEY->[CURRENT_USER or LOCAL_MACHINE]->SOFTWARE->MICROSOFT->WINDOWS->CURRENT VERSION->LOOK FOR THE RUN AND RUN ONCE FILES HERE AND INVESTIGATE WHAT IS IN THERE
This is just my opinion and others will probably disagree. Apologies for not being able to pin the DNS addy changing on anything in particular but I hope this has been somewhat helpful.