Is the unknown PC server connected to my computer a "phishing" website?

Question

My facebook account was recently hacked through a phishing scam. I'm becoming much more conscious of unusual behavior on my computer since then--and I noticed that on my finder sidebar, there's this PC server that's showing up as connected to my computer. Try as I might, I can't disconnect or get rid of it in any other way, and I'm frightened that it's a result of this phishing fiasco. The name of the server is preferre-2f6685.
Can somebody tell me what this thing is and if it's malicious, how to get rid of it?

Answer 1

It's a guessing game unless you do some investigating.
Any number of devices can show up as an unknown device under the sharing section of the finder. It is very, very unlikely that a virus is causing that device to show up on the side - especially one that may have come from Facebook...
I would recommend checking your router's DHCP client tables for wired and wireless networks.
That should tell you all the devices that are attached to your network that have IP addresses.
If that doesn't help you solve the mystery, then you should download nmap/Zenmap and do a port scan.
I just wrote a post all about this on another thread... Here it is:
There are several ways to go about finding out what the secret unknown device is...
1. Check your network for attached devices
Physically look at what is connected to your network by seeing what is plugged into your router or modem.
2. Check your router for DHCP clients
Your router will have some sort of configuration page that you can check from your computer. This will tell you what is attached and communicating with your network wired or wirelessly.
The DHCP client list shows what devices are getting IP addresses automatically (if assigned manually, they will likely not show up here). The instructions for this are different (but not too different) from router to router. Common brands for routers include Netgear, Linksys, and Apple.
On an Apple Airport wired and wireless DHCP "clients" are listed separately to find the wired ones go to Advanced > Logging & SNMP > Logs and Statistics > DHCP Clients and to find the wireless ones, look under AirPort > Summary > Wireless Clients. For another brand, you'll have to Google it.
3. Run a Serious Network Scan with Nmap/Zenmap
This is almost overkill for trying to find out what is on the sidebar of your Finder - but, nmap is an the best utility for network scanning. It can be downloaded from:
http://nmap.org/download.html#macosx
It comes with a graphical interface called Zenmap and a command line tool. Personally, I prefer the command line version but they both work the same. Zenmap does require X11.
Either way, you can scan your network if you know the IP address of your own computer while it is connected.
If you need to find your IP address - you can find this by EITHER opening a terminal and typing ifconfig OR by going to System Preferences > Network then choosing your Airport or Ethernet (whichever is connected) and looking for your IP address. It should be in the format ###.###.###.### - common IP subnets include 192.168.1.###, 192.168.0.###, and 10.0.1.### - when you've found your IP address, you can now do an nmap/Zenmap scan for all IPs within your subnet. Not only will this tell you what network devices are attached, but also it will try to detect what type of device and what operating system is being used.
To find ALL the devices attached to your network, you will have to search the entire range of your subnet - the subnet is the first three groupings of your IP address. For my computer's IP 192.168.1.5 this would be 192.168.1 and since the minimum address for an IP is 1 and the max is 255, I will be searching in the range 192.168.1.1-255 (if my IP was 10.0.1.101 or 10.0.1.5 then I would search 10.0.1.1-255).
If I'm using Zenmap I will make my target 192.168.1.1-255 and I will choose Quick scan from the profile - just to get an idea of what IPs are in use. 10 seconds later - Presto! A list of all the devices attached to my network.
Feel free to upload the list here and let me take a look if you have any trouble reading it yourself.
You can also do a scan by entering the following into the Command field of Zenmap or by running this in the Terminal (please adjust your subnet accordingly):
nmap -O -sA 192.168.1.1-255
This will attempt to get more information out of the attached devices, such as, what operating system they may be running.
Start with that and post back here to let me know what you find.