let me explain my problem. The wifi on my macbook suddenly stopped working so tried to use my usb wifi adapter on a linux VM. But the funny thing is that nothing works on the guest vm either...

Well funny thing because, I get an IP from my DHCP and I can connect to the internet, but only to google's websites! exemple: ping google.com = ok and ping bing.com = nok .

Obviously, the rest of my network is working fine and I only get issues on this particular mac.

Can something affect my host file or something like that on OSX and affect my linux as well ? Have you ever seen such malware? I got pirated several before!

  • Should that question move to the network eng. SE site? It's probably nothing to do with viruses... – Steve Dodier-Lazaro Jul 11 '14 at 19:17

If the host machine has a damaged hosts file, any traffic going from the guest VM, through the host, will encounter this damaged hosts file before it accesses the internet. EVEN IF the guest is using a USB wifi adapter, it will still have to interact with the hosts host file.


VM commands get redirected through the host OS. Some stuff may go direct to the CPU depending on what kind of virtualization support your system has, but that is still only granted at the will of the host OS. If the host OS is compromised, then the virus can potentially impact anything running within it, including a virtual other process. Sandboxing tries to keep bad things in the VM, it doesn't keep bad things on the outside from impacting a clean VM.


You might need to change some computer habits if you've been "pirated several times already", but to answer your question, yes it's definitely possible for a virus on your host to have adverse effects on a VM. The VM uses resources allocated to it by the host machine. If your Guest OS has direct access to your host file system for example, it's entirely possible to have adverse effects. Regardless, you need to clean up the host OS.


Your problem probably has nothing to do with viruses. If you can only access a specific domain, it may be that this one (for whatever reason) is inside your DNS cache but you can't reach any other site because your DNS server is unresponsive.

  1. I would start by using a network analysis utility (such as Wireshark) to determine whether DNS queries succeed or fail on the host.

  2. If DNS queries can be sent and answers received but you don't get correct information from your server, I would try an alternative DNS server in case the one you're using has been compromised or is being buggy. I would also try to connect that machine on an entirely different network because your gateway might get in the way (no pun intended).

  3. If I still can't use any DNS, I would boot on a LiveUSB/LiveCD (a simple Linux one or maybe a OSX one but I'm not sure how legal that'd be) to check whether the issue concerns the hardware or the OS. Hardware issues that only affect DNS are very extremely unlikely.

  4. If I can get correct DNS answers on the Live OS then the issue is with the Macbook's OS (misconfiguration or indeed virus) and you'll need to use whatever diagnosis and security utilities you can find to identify it, or in the worst case to reinstall your OS.

  • Thank you i will look into that. Ive got a MacBook air no cd – boby lapointe Jul 11 '14 at 21:41
  • Try a LiveUSB or a PXE boot then. Have fun! – Steve Dodier-Lazaro Jul 12 '14 at 3:09

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