I recently had an incident of malware/virus/trojan infection of my laptop. With help from BC experts, it seems that the infection has been at least partially removed, if not completely. However, I wonder if it's possible that a malware/trojan can leave a backdoor UN-closed EVEN AFTER it's been removed/quarantined.
The reason I am asking this is based on two observations below. Another fellow and I, both residing in NYC, NY USA, have recently had our "internet" invaded.
The other fellow had TWC and Verizon as his/her home internet service providers. When s/he connected via TWC WIFI, URL "google.com" would get redirected. When s/he connected through Verizon (assuming direct connection), it appeared that the redirecting did not happen.
For me, URL "google.com" gets redirected to "google.co.il" when I search it from home, where I also use TWC WIFI as my internet provider. However, if I do it from my company (through company's WIFI), URL "google.com" goes to "google.com" !!
(1) *IF* an internet service provider has their systems compromised, wouldn't ALL users see this redirecting ??? (but why aren't many people reporting it)
(2) *IF* only a handful of people encounter this "invasion" with the same internet service provider, does this mean only those affected have their computers compromised? But since my computer has been cleaned up, does this mean while the "backdoor creator" has been removed, a backdoor has been permanently created (which renders my computer vulnerable without reinstallation) ?
Any remedy if it's the latter case. Any help will be appreciated. Thank you.