Over 300 network connections from/to a mac?

[AgentTadpole]

Hi,

So, my sister's Mac has over 300 active network connections going at all times when it's on. I'm not particularly good with Mac, and nor is my sister, so I don't know whether this is some thing that Apple devices do (considering iDevices keep everything running in the background), or whether we should be looking for a virus?
We've run a virus scanner, it only found some phishing emails which I don't think could be the cause.
Whatever is doing this, it is slowing down our whole router to the point that I can't even imagine doing anything more than, well, asking for help in a Mac forum.

Does anyone have any idea of what's causing this and how we could fix it? (Step by step instructions please. Remember, not good with Macs)

Thanks in advance

 

[simsaladimbamba]

• 1. What Mac OS X version do you use?
• 2. What application tells you that number of 300 connections?
• 3. How are you connected to what network? Wirelessly or wired to a router in your home or a something else?
• 4. Currently there are zero viruses affecting Mac OS X in public circulation, but there are other kinds of malware existing, that can infect your Mac.
  To learn more about malware in Mac OS X and what steps can be taken to protect yourself, read the following F.A.Q.:
  
  Mac Virus/Malware Info by GGJstudios​

 

[ElectricSheep]

The command sudo lsof -i when entered into a Terminal will give you a list of all open network connections as well as what user and process is associated with that connection. You will need an administrator password, and the output could be quite large. You can redirect it to a text file:

sudo lsof -i >> output.txt

The PID numbers in this output can be cross-referenced with the output of ps -Ax to determine what command was used to execute the program in question.

 

[AgentTadpole]

The Mac OS X version is 10.8.2.

I didn't use any program, I used the web interface of my D-link router, which has always been extremely reliable in the past, it's never shown fake/ghost info.

The Mac is connecting wirelessly to a D-link router, which I used to work out how many connections it had.

Upon further inspection of the router's Internet Session's page, I discovered that almost all of these connections are using port 52020 over UDP. They are all going to seemingly random IPs and ports, for example: 77.49.73.90:34618, 128.68.1.164:18828, 14.200.149.32:27345. Hopefully some of this helps.

 

[ElectricSheep]

The Mac OS X version is 10.8.2.

I didn't use any program, I used the web interface of my D-link router, which has always been extremely reliable in the past, it's never shown fake/ghost info.

The Mac is connecting wirelessly to a D-link router, which I used to work out how many connections it had.

Upon further inspection of the router's Internet Session's page, I discovered that almost all of these connections are using port 52020 over UDP. They are all going to seemingly random IPs and ports, for example: 77.49.73.90:34618, 128.68.1.164:18828, 14.200.149.32:27345. Hopefully some of this helps.

Large numbers of connections like this indicate some P2P behavior, but that could be anything. Please see my previous comment to find out what is opening these connections.