https://live.paloaltonetworks.com/t5/advanced-threat-prevention/dns-sinkhole-what-constitutes-investigation/m-p/282165#M626 <P>I have implemented DNS sinkholing and am curious what constitutes investigation. I am seeing some clients hitting the sinkhole but only for a short period (1-2 minutes or less).</P><P>&nbsp;</P><P>I'm not sure if these could be drive-by download attempts, or what they are. I would expect an infected machine to keep trying but these machines have the short lived sinkhole traffic then, even after several days, do not reappear.</P><P>&nbsp;</P><P>Excuse the ignorance. Any opinions would be appreciated. Thanks so much.</P><P>&nbsp;</P><P>This is my first post on here so hopefully I'm in the correct discussion group. I'm still learning my way around.</P> Fri, 09 Aug 2019 23:55:32 GMT mbleckert 2019-08-09T23:55:32Z https://live.paloaltonetworks.com/t5/advanced-threat-prevention/dns-sinkhole-what-constitutes-investigation/m-p/282165#M626 <P>I have implemented DNS sinkholing and am curious what constitutes investigation. I am seeing some clients hitting the sinkhole but only for a short period (1-2 minutes or less).</P><P>&nbsp;</P><P>I'm not sure if these could be drive-by download attempts, or what they are. I would expect an infected machine to keep trying but these machines have the short lived sinkhole traffic then, even after several days, do not reappear.</P><P>&nbsp;</P><P>Excuse the ignorance. Any opinions would be appreciated. Thanks so much.</P><P>&nbsp;</P><P>This is my first post on here so hopefully I'm in the correct discussion group. I'm still learning my way around.</P> Fri, 09 Aug 2019 23:55:32 GMT https://live.paloaltonetworks.com/t5/advanced-threat-prevention/dns-sinkhole-what-constitutes-investigation/m-p/282165#M626 mbleckert 2019-08-09T23:55:32Z https://live.paloaltonetworks.com/t5/advanced-threat-prevention/dns-sinkhole-what-constitutes-investigation/m-p/284621#M632 <P>Hello,</P><P>The answer is it dpends, however for our company, they all do. Check the unified logs around the same time as the sinkhole and see what may have triggered it. Also do research on the domain with a 3rd party such as virtustotal.</P><P>&nbsp;</P><P>Regards,</P> Thu, 22 Aug 2019 15:11:32 GMT https://live.paloaltonetworks.com/t5/advanced-threat-prevention/dns-sinkhole-what-constitutes-investigation/m-p/284621#M632 OtakarKlier 2019-08-22T15:11:32Z