When you are surfing on internet, watch out with unofficial sites claiming to let you download free tunnelling documents. For example when I searched for the proceedings for the Rapid Excavation and Tunneling Conference 2019 that I was interested in, I came across this Russian site offering free download. Of course I did not download.

In recent times some sites appeared, mostly from Russia (I mean with Russian domain names with .ru extension) and some with Polish domain name extentions (.pl). Another trick especially by Russian and Chinese hackers is, they re-register expired European domain names and try to hack you from there. For example, a domain name with a Danish name say Bilenbilenbilenbilen.dk (I am making this up. At the time of writing this, there is no such internet site). Because you see it is a Danish site, you are more likely to trust it and click it. At least If you are Danish. They also try it with Italian sites, German sites, Spanish sites etc.

Just resist the temptation not to download any PDF files from unofficial sources.

Downloading copyrighted material without the consent of the owners not only illegal and unethical but also if you download things from such sites, most likely you will also be getting some computer virus. These files are downloaded mostly in PDF format, which is a preferred format for internet criminals.

Once you download it, your computer is likely to turn into a zombie computer spreading fake news, without you even noticing, as a part of Putin's massive disinformation network.

Take care of yourselves in these difficult days.