Regecish.net is a domain designed to deliver various questionable content to its visitors. Users are extremely unlikely to land on the site intentionally. Instead, almost always they will be taken there as a result of forced redirects caused by a previously visited site or due to a PUP being present on their computers or devices.
PUPs rely on misleading and deceptive distribution techniques and oftentimes users may not even realize that such an application is being installed. Two of the most common methods include bundling - the PUP is added as a preselected choice inside the installation process of another program, or hiding inside a fake installer/updater for a popular software product. The main goal of any PUP is to generate monetary gains for its creator. It can do so by having the functionality of adware, a browser hijacker or both. Adware applications are concerned with delivering as many intrusive and unwanted ads as possible predominantly. Browser hijackers, on the other hand, take over specific browser settings to generate artificial traffic towards a fake search engine, in most cases. PUPs also are almost always equipped with a certain degree of data-harvesting capabilities.
The user's browsing history, all conducted searchers, any clicked URL could be tracked, packaged, and then uploaded to a remote server. In the most threatening cases, the PUP attempts to access sensitive information that has been saved into the affected browser. This could include banking and payment data, as well as credit/debit card details.
While some PUPs do have useful traits, it is strongly recommended not to underestimate the risks they pose. The best way to deal with a PUP is to scan your computer with a reputable anti-malware solution and then remove any of the suspicious applications that are detected.