Pop Ups still happening after security settings set - HELP!!!

Question

We have a Mac OS-X 10.7.5. I am having pop ups EVERY time I log into Safari even after I've checked "block pop ups" in security in Safari. I've installed Adguard, and now, I will click on a site i want to go to and adguard blocks it, but never opens the page because the malware sites like "mackeeper" are jumping in before the real site is opened. This is getting crazy. And a pornographic pop up happened and I have kids. Thank God it was me on here when it popped up. Something somehow has gotten into this computer. So. My question I guess is, can I uninstall Safari and install Firefox or something else and have this not happen anymore? Or uninstall Safari and re-install?? Thanks so much for any help. This is really awful.

Answer 1

First, you do not need to download unknown software to solve this problem.
You may have installed the "VSearch" trojan, perhaps under a different name. Remove it as follows.
Malware is constantly changing to get around the defenses against it. The instructions in this comment are valid as of now, as far as I know. They won't necessarily be valid in the future. Anyone finding this comment a few days or more after it was posted should look for more recent discussions or start a new one.
Back up all data before proceeding.
Step 1
From the Safari menu bar, select
          Safari ▹ Preferences... ▹ Extensions
Uninstall any extensions you don't know you need, including any that have the word "Spigot," "Trovi," or "Conduit" in the description. If in doubt, uninstall all extensions. Do the equivalent for the Firefox and Chrome browsers, if you use either of those.
Reset the home page and default search engine in all the browsers, if it was changed.
Step 2
Triple-click anywhere in the line below on this page to select it:
/Library/LaunchAgents/com.vsearch.agent.plist
Right-click or control-click the line and select
          Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item named "com.vsearch.agent.plist" selected. Drag the selected item to the Trash. You may be prompted for your administrator login password.
Repeat with each of these lines:
/Library/LaunchDaemons/com.vsearch.daemon.plist
/Library/LaunchDaemons/com.vsearch.helper.plist
/Library/LaunchDaemons/Jack.plist
Restart the computer and empty the Trash. Then delete the following items in the same way:
/Library/Application Support/VSearch
/Library/PrivilegedHelperTools/Jack
/System/Library/Frameworks/VSearch.framework
~/Library/Internet Plug-Ins/ConduitNPAPIPlugin.plugin
Some of these items may be absent, in which case you'll get a message that the file can't be found. Skip that item and go on to the next one.
This trojan is distributed on illegal websites that traffic in pirated content. If you, or anyone else who uses the computer, visit such sites and follow prompts to install software, you can expect much worse to happen in the future.
You may be wondering why you didn't get a warning from Gatekeeper about installing software from an unknown developer, as you should have. The reason is that this Internet criminal has a codesigning certificate issued by Apple, which causes Gatekeeper to give the installer a pass. Apple could revoke the certificate, but as of this writing, has not done so, even though it's aware of the problem. This failure of oversight has compromised both Gatekeeper and the Developer ID program. You can't rely on Gatekeeper alone to protect you from harmful software.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination  command-C. In the Finder, select
          Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.