I keep losing my internet connection due to an attempted software upgrade installation that I did not initiate. I have to restart to get internet back, but then it happens again the next day or so. As the computer starts to reboot it flashes a prompt asking if I want to abort installation, but it is not there long enough for me to react. Anybody else have a similar problem? Know a solution?
iMac, OS X Yosemite (10.10.3)
You may have installed the "Genieo" or "InstallMac" ad-injection malware. Follow the instructions on this Apple Support page to remove it.
Back up all data before proceeding.
Malware is always changing to get around the defenses against it. In addition to the files listed in the support article, you may also have some of the following:
~/Library/LaunchAgents/com.Installer.completer.download.plist
~/Library/LaunchAgents/com.Installer.completer.ltvbit.plist
~/Library/LaunchAgents/com.Installer.completer.update.plist
~/Library/LaunchAgents/com.spigot.SearchProtection.plist
~/Library/Application Support/IM.Installer
Removing these files, if they exist, is optional if you've already followed Apple's instructions.
One of the steps in the article is to remove malicious Safari extensions. Do the equivalent in the Chrome and Firefox browsers, if you use either of those.
After removing the malware, remember to reset your home page in all the web browsers affected, if it was changed.
If you don't find any of the files or extensions listed, or if removing them doesn't stop the ad injection, then you may have one of the other kinds of adware covered by the support article. Follow the rest of the instructions in the article.
If you find Apple's instructions too hard to follow, ask for an alternative that doesn't require you to trust a black-box application without knowing what it does.
Make sure you don't repeat the mistake that led you to install the malware. Chances are you got it from an Internet cesspit such as "Softonic," "CNET Download," or "SourceForge." Never visit any of those sites again. You might also have downloaded it from an ad in a page on some other site. The ad would probably have included a large green button labeled "Download" or "Download Now" in white letters. The button is designed to confuse people who intend to download something else on the same page. If you ever download a file that isn't obviously what you expected, delete it immediately.
In the Security & Privacy pane of System Preferences, select the General tab. The radio button marked Anywhere should not be selected. If it is, click the lock icon to unlock the settings, then select one of the other buttons. After that, don't ignore a warning that you are about to run or install an application from an unknown developer.
Still in System Preferences, open the App Store or Software Update pane and check the box marked
Install system data files and security updates (OS X 10.10 or later)
or
Download updates automatically (OS X 10.9 or earlier)
if it's not already checked.
Thanks, Linc. However, this does not appear to be an ad-injection malware issue, and I could not find "Genieo" or "InstallMac" on my machine. I'm fairly careful with downloads to be sure it is a trusted source. This problem just occurs randomly about every few days. For no particular reason I will be unable to connect to my server to get internet or email. When I restart, the problem goes away... for awhile. A curious prompt appears on my screen just before restarting indicating that installation of a download failed and asking if I want to abort the download. Most of the time it flashes by too fast for me to react. But the few times I've been able to click the "abort" button, it seems to have had no lasting effect. I'm baffled. But thanks for your suggestions. Any others you might have would be most welcome.
an attempted software upgrade installation that I did not initiate.
Check your App Store settings in System Preferences>App Store
Also open up the App Store app & click the update tab. What does it show?
Repeated internet disconnect due to attempted unknown download.
