After a hacker attack on your account or computer, an attacker, one way or another, will leave some "digital fingerprints" with which you can identify such an attack, however, hacking your digital space is not always goal-oriented, which means, more often than not, viruses and without much effort to hide their activity.
Antivirus / Firewall is disabled
The first sign, which should be watched first. Antivirus or firewall is disabled by a hacker in order to as much as possible to weaken the security of your computer. However, do not count on the "red traffic light" icons of your antivirus, hackers may well damage the files needed to run this program, so you'll see an error message or you can not see it at all. The latter means that the antivirus can be started and stopped at random. In this situation, you can try to disconnect from the Internet, run the system in "safe mode" with subsequent scanning and, of course, restore the system, or better - completely reinstall it.
Changing passwords
After hacking your account on any website, hackers very often change your password and e-mail, to which the account is tied. Thus, you are completely shielded from managing your account and accessing the support service. If you are lucky, the website gives access to it even to an unregistered user and today is not a day off, then, be patient with it, as long as you provide all the necessary information for recovery, it will be processed in the order of the queue and confirmed (which also happens not the first time), the attacker, for sure, will already have time to do with your account all that was required of him.
Newsletters from your account or mailbox
Very often, attackers create a whole network of broken accounts, the main task of which is spam, phishing and trolling. Sometimes, less noticeable actions, such as subscribing to a group or reposting a record, can also be used.
In spite of those actions that have been committed without your participation, but on your behalf, you must notify the support service about them, which will help to prevent the blocking of your account and prevent further work of hackers. After notifying support, you should change absolutely all of your passwords for websites and scan the system with antivirus software.
Detecting unknown programs
In fact, from the point of view of the system administrator there should be no problems at all. From the point of view of a typical user who has hundreds of different programs, problems can arise. Therefore, the first tip: install only the necessary software. Second, if you are suspicious, look at the name of the process in the task manager, then enter its name at this site and you will see the level of its danger.
Redirecting to other sites and the sudden slowdown of the computer
These are the two most common cases. In the first case, most likely when you visit a site you will be redirected either to an advertising resource or to a fake (site-fake), the purpose of which is to get the password from the account on the original site, or to a phishing site where you will be "asked" for data from the card to unlock the site. The second one can say that your computer is used for the hidden secret of crypto currency