Internet is the primary source of Viruses, malware, etc. A website may intentionally force you to download a malicious file or a crook may ask you to open a shortened malicious URL. In the 1st case, it's up to you to download the file or not but in the second case especially when the page executes a dangerous code or makes the browser download a tiny harmful executable file, you can't do anything.
Before opening the shortened URL in the browser, it is a good practice to see the link's unshortened version. If you don't do so and if the page that the link opens is malicious, the page may force the browser to download a self-executable virus or malware or install adware.
The Unshorten URL tool of Crawlcenter is easy to use. All you have to do is enter the shortened URL in the textbox and click the submit button. Now, wait for a few seconds. CrawlCenter will display the Unshortened version of the entered URL. If you think that the unshortened link opens a malicious page, you can use our source code viewer tool to see the page's HTML/JS code