How to know if someone is trying to access my PC unauthorizedly?

Asked By 130 points N/A Posted on -

My friends are using my laptop whenever they visit me at home. I was shocked when I saw some of my original pictures stored on PC are showing on a search engine.

I asked my friends if they touched my files, but they said they didn't. I trust them very much so I started thinking maybe someone is trying to break into my computer anonymously, and that's why someone was able to get those pictures.

Is there a way to check if someone is trying to access my computer unauthorizedly?

Please let me know your inputs about this?

Any suggestions are very much appreciated.

Thank you very much in advance.

Best Answer by Peter Kent
Best Answer
Best Answer
Answered By 0 points N/A #112512

How to know if someone is trying to access my PC unauthorizedly?


Accessing other computer unauthorizedly somewhat becomes a villain in cyber industry. The first thought that comes in our mind is theft. They steal information including your password, bank account, deceived corporations and other worst case scenarios.

People who do this can be scaled from novice to expert; there are many kinds of intruders. There are cases that you can easily discover if someone is trying to access your computer anonymously but other times you cannot tell if someone is trying to break into your computer.

These intruders enjoyed in discovering more on how the computer operates and they even consider doing this illegal job as a form of art. Others consider this as a day to day challenge in the world of programming, testing their skills and seeing their skills evolving.

They say that they only do it to show off their capabilities on how far they can go in terms of breaking the boundaries of cyber communities.

Corporations and other big companies hire some computer intruders as one of their tech support staff. They use their  skills to test the system security if there are any holes on it so that they can easily create some solutions on it.

So how can you know if your computer is being accessed unauthorizedly? If you had a feeling that something is different with your computer you can check the network statistics of your computer by typing netstat –aon under command prompt, check the connections port that ranges from 49151-65534 where these ports are not safe.

Trace the source of the IP and check if those are trusted. There are signs if someone is trying to break into your computer's software:

  1. If your computer performance drastically drops.
  2. Your computer settings suddenly change and even worse.
  3. When web browsing, you are being directed to the site that you don’t want.
  4. Pop-ads that won’t stop.
  5. Files have been altered or won’t open.
  6. Deleted files but you did not delete them.
  7. High usage of network.
  8. Abnormal CPU usage.
  9. Computer shutdown on its own.

There are different kinds soft wares that can help you in protecting your computer against intruders. Strengthening your firewall is the best solution; you can use ZoneAlarm firewall. It provides protection against virus, e-mail and has a tool for Identity theft protection. Use Antivirus and Anti spyware that is up to date.

Intruders use Trojan to take control over your computer. Check  the system log to know what is happening in your computer, if you discover that there are new programs installed that you do not know then investigate. Always keep your operating system updated. In Windows they provide updates which is intended to increase your system security.

Answered By 0 points N/A #112513

How to know if someone is trying to access my PC unauthorizedly?


Hi! Ruth Nelson,

These intruders usually go for passwords, email accounts, financial information, log-in information to financial websites, etc. Photos are probably one of the least to be targeted, especially if the photos are not renamed to describe the photo, unless maybe specified by the folder they are in or if those photos are what the intruder is really after.

Tracking down a prowler, especially on manipulated passwords are difficult. You should just be glad that there wasn’t anything else that was taken or used.

Here are some ways you can find out that your someone is trying to access your computer unauthorizedly and how you can protect yourself:

1. Enabled ports – You can check ports that are enabled. If some ports are opened and is used by an unrecognized application, that could be an indication that someone is trying to steal the information on your computer.

XP: Click Start > Run

Vista/7: Click Start > Search box

  1. Type “cmd” press enter
  2. In the command line, type “netstat –ano” press enter
  3. Take note of all the Enabled state and their PID
  4. Press Alt+Ctrl+Del to open the Task Manager
  5. In the Task Manager, click "View" > Select Columns > Check PID (Process Indentifier)
  6. Now match the PID from the command line window to the PID of the "Task Manager"
  7. Usually, the ones that you’ll see are your browser and your Antivirus.
  8. If there are other processes that show enabled in the command line window, Google that process and see if it is a valid application or not.
  9. End it if not and run a virus scan
  10. Look for a way to remove it manually if needed.

2. Check your resources – Another sign to consider is if your computer unusually uses a lot of resources. Sypwares, keyloggers, rootkits, etc. have been known to be taken up a huge amount of memory resource because they do stuff in the background.

  1. Close all programs/ applications that you are using.
  2. Press Alt+Ctrl+Del to open the "Task Manager".
  3. Check CPU Usage or the green box in the task bar.
  4. If it says that you are using about 50% or more than that even and if you don’t have any programs open, then there is something suspicious going on in your PC.
  5. Do solutions #2 and #3
  6. It is also a good practice to Google the processes that you don’t recognize to make sure if they’re safe or not.

3. Redirects and pop-ups – When surfing the internet, if you notice that when you search or type any web address, you suddenly get redirected to another website, and/or you get pop ups of the same advertisements/websites, then something nasty is in your computer. This infection may also lead to attacks and remote access to your computer.

4. Check your email accounts – Since attackers use email as means of transportation of key logs, files, etc. See if you have any unrecognized sent email, especially if you’re using Outlook.

5. Virus Scan in Safe Mode – There are some virus and other Malware than have been known and programmed to hide themselves from the Antivirus, a good example for this is a Trojan. As the name suggests, it disguises itself as a safe application but does something nasty in the background.

Most Malware are not operational in "Safe Mode", therefore there is a better chance that the Antivirus or Antimalware can detect these malicious software and get rid of them.

  1. Update your Antivirus
  2. Restart your computer and as soon as it lights up hit F8 a few times to get to the "Windows Advanced Options Menu".
  3. Choose "Safe Mode"
  4. Choose your operating system.
  5. Login as the "Administrator"
  6. Do another scan of your PC
  7. Finding some Trojan, worm, spyware, rootkit, etc. are indicative of an attacked computer.

6. Other Malware – If you have not found any virus and as mentioned above, it may not be a virus at all. It could be a worm, rootkits or other malicious software that is changing your settings. Some Antivirus software cannot detect other Malware or at least some of it. You need another layer of protection to make sure your PC is really Malware free.

Try some of these popular Antimalware, Antispyware and Rootkit Scanners:

  1. Spybot Search and Destroy
  2. Malwarebyte’s Antimalware
  3. Ad-Aware
  4. Sophos Anti-Rootkit
  5. GMER Rootkit scanner and remover

Download and install them. Update and run a scan. Again, finding some Trojan, worm, spyware, rootkit, etc. are indicative of an attacked computer.

7. Replace Antivirus – If you really suspect that someone is trying to intrude on your computer, then it’s probably time to replace your Antivirus. As you have seen, your Antivirus was not effective in stopping this attack or even the software that got in to your computer to allow this illegal deed in the first place. Free Antiviruses are good but paid versions are always better, which is why they cost money.

Some of the reputable Antiviruses are:

  1. Kaspersky
  2. BitDefender
  3. Avira
  4. F-Secure

8. Always update – Always install updates to your computer and the applications you have. Believe it or not, there are quite a number of flaws in computer systems and applications. These flaws are exploited by attackers making the use of them to their advantage. Take for example the Adobe Photoshop.

This application has had a security vulnerability which has been reported to be used by attackers to get in or send malicious software to PC’s. Security updates by Microsoft are important patches to avoid any kind of Malware attack.

9. Password protect your folders – There are numerous third party software that allows you to lock, encrypt, and shred your files and folders. They can also monitor if someone is trying to steal your information , clean history and can hide themselves so that it won’t be known to others that you have these kinds of software installed.

Some of the well-known file and folder security software:

10. Reformat – If you are definitely sure that you have been victimized by intruders, then the only 100% sure way is to start with a clean slate. Reformat your hard drive to erase everything and reinstall using genuine software. Update the installation, install an Antivirus FROM A CLEAN SOURCE, update it and scan every removable media you need before using.

As mentioned above, trying to find out if someone is intruding on your computer is not an easy task. Intruders don’t usually leave any trace so they can come back, unless they intentionally left it there as a signature.

Good luck!

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