I can tell you some steps to perhaps resolve the SMB issue (this is not related to how you connect to the internet). The steps outlined below will turn off the SMB v1.0 service on your machine which is what the Wannacry and similar Ransomware variants use to infect your machine.
If you are using Win 7 you need to run some commands from the Command prompt (admin privileges). So first do these steps:
- Click Start, click All Programs, and then click Accessories.
- Right-click Command prompt, and then click Run as administrator.
- If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
Once the Cmd box is open enter these commands one after the other (feel free to copy and paste) pressing enter after each:
sc.exe config lanmanworkstation depend= bowser/mrxsmb20/nsi
sc.exe config mrxsmb10 start= disabled
If using Win 8, 8.1, or 10 you can use the search bar at the bottom (Cortana) and type Control Panel then from the list select the one at the top that says Control Panel Destop App. When “Control Panel” opens up go to “Programs and Features” and when it opens select “Turn Windows features on or off”. When this list populates untick the “SMB 1.0/CIFS File Sharing Support” and then click “OK”.
The DDoS Amplifier part is more difficult. It could mean that your settings on a router are not correctly setup and are allowing traffic in and out that shouldn’t have access. It could also mean that the DNS servers you use have been hacked. Or perhaps at least one of your computers/tablets/phones may have been infected/hacked and is now part of a Bot network which would mean you need to clean them up to ensure they are not infected.
Check your Router/Modem to make sure the NAT (Network Address Translation) and firewall are on if not turn them on. Change the default login name and password for the Router/Modem and keep a record of it. Ensure you are using WPA or preferably WPA2 to secure your Wifi Traffic, I note you posted you are but if you have been hacked things could have been changed (not a big risk where you say you are but still worth doing).
Ensure you have a decent Antivirus program on your PC (not necessarily a paid one) try Avira, Avast, (these previous 2 can be easily setup from https://ninite.com), Bitdefender (has a free version), Norton, Panda, Kaspersky or Trend Micro are all good options but some do cost and please don’t rely on Microsoft’s Defender/Security Essentials. McAfee is a bit resource hungry and can be a little less than what you want when seeking good results but if you like it then try an online scan as well such as Trend’s Housecall:
Make sure your PC’s firewall is turned on, The Windows’ one is fine but there are others out there eg Comodo or Zonealarm Free and some Security Suites come with their own firewall.
Once you have determined what AV product you want and have installed it you need to install the free version (you can buy the Pro version but there is no need) of Malwarebytes (https://www.malwarebytes.com/mwb-download/thankyou/).
HOW TO ENTER SAFE MODE IN WINDOWS
To get to safe mode in Win 7 you need to restart your machine and as it boots up keep pressing (multiple presses not a single long one) the F8 key, if successful you will see a list of start up options and you just need to move to the Safe Mode with Networking one and press Enter. If not successful just restart and repeat until you get it.
For Win 10 it is a bit different to get to this mode. You have to click the Setting icon (looks like a cog) from your Start menu, then click “Update & Security” then click “Recovery” then click “Restart now” under the “Advanced start-up” paragraph. At this point your machine will restart and you need to Click " Troubleshoot" from the options then “Advanced options”, click “Startup Settings” click “Restart”. Your PC will restart and you will be offered a list of options and in this case press the number 5 on your keyboard.
Enter “Safe Mode with Networking” on your Windows machine/s run Malwarebytes, update it, then in it’s settings tab ensure scan for rootkits is ticked and finally run a scan. If it detects any problems allow it to clean them up. It may ask you to restart to finish cleaning up but just delay the restart until you do the next step.
After finishing the Malwarebytes scan then you should go to the Hosts file found in “%WINDIR%\system32\drivers\etc” (just copy and paste that entry into file explorer without the quotes) and check if there are entries there beyond “127.0.0.1 localhost” (if any others have a # before them they can be ignored). If there are other entries check them out by doing a web search to see if they should be there. The Hosts file cannot normally be altered but you can right click it, select properties, and uncheck the “Read only” setting and remove any bad entries. Do not remove the 127.0.0.1 localhost one it is very important.
After this has been done you can restart your PC and it will restart in normal mode. Once you are logged in run a complete Virus Scan to ensure anything missed gets caught and if you wish run an online scan.
On the phones look to use a decent AV product with well respected names eg AVG, Avira, Kaspersky (many can be used free and ensure you get the “real” ones). Then scan your phone. If Apple iPhones I am not sure what is available for them. If you really are unsure if everything is ok you can do a factory reset but be aware this will delete all your saved data, so back them/it up just in case before you do the reset.
If the tablet/s are Android again use the same as the phones and if Windows based use the same as on the PC. Again on an Android Tablet you can do a factory reset and again be sure to back up beforehand.
I hope these hints and steps help get your problems sorted out.