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dmg installer Virus?

I have been having this weird problem on my macbook pro where every second or third dmg I download and attempt to open comes up as Installer no matter what the program is actually called and when I click on install it starts installing 7zip. Im just assuming this is some kind of virus but I would love some help because some of the programs I have downloaded are very large and I hate to think I have wasted many gigs on nothing!

MacBook Pro, OS X Yosemite (10.10.5)

Posted on Mar 20, 2016 5:10 AM

Reply
11 replies

Jun 30, 2017 7:25 PM in response to Linc Davis

This "makes you more vulnerable to attack, not less" is a bit extreme and complete nonsense, as a technician since the 70's and working on every iteration of PC and Mac since that time its statements like this that can sometimes be the root cause of some users getting issues thinking they are immune. The rest of your help is good and there is no need for such coverall rubbish statements that include "all" such anti-malware programs.

Mar 20, 2016 7:17 AM in response to Koppa2000

You may have installed ad-injection malware ("adware").

Don't use any kind of "anti-virus" or "anti-malware" product on a Mac. There is never a need for it, and relying on it for protection makes you more vulnerable to attack, not less.

Back up all data first.

Some of the most common types of adware can be removed by following Apple's instructions. But before you follow those instructions, you can attempt an automatic removal.

If you're not already running the latest version of OS X ("El Capitan"), updating or upgrading in the App Store may cause the adware to be removed automatically. If you're already running the latest version of El Capitan, you can nevertheless download the current updater from the Apple Support Downloads page and run it. Again, some kinds of malware will be removed—not all. There is no such thing as automatic removal of all possible malware, either by OS X or by third-party software. That's why you can't rely on software to protect you.

If the malware is removed in your case, you'll still need to make changes to the way you use the computer to protect yourself from further attacks. Ask if you need guidance.

If the malware is not removed automatically, and you can't remove it yourself by following Apple's instructions, see below.

This easy procedure will detect any kind of adware that I know of. Deactivating it is a separate, and even easier, procedure.

Some legitimate software is ad-supported and may display ads in its own windows or in a web browser while it's running. That's not malware and it may not show up. Also, some websites carry intrusive popup ads that may be mistaken for adware.

If none of your web browsers is working well enough to carry out these instructions, restart the computer in safe mode. That will disable the malware temporarily.

Step 1

Please triple-click the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:

~/Library/LaunchAgents

In the Finder, select

Go Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. Press return. Either a folder named "LaunchAgents" will open, or you'll get a notice that the folder can't be found. If the folder isn't found, go to the next step.

If the folder does open, press the key combination command-2 to select list view, if it's not already selected. Please don't skip this step.

There should be a column in the Finder window headed Date Modified. Click that heading twice to sort the contents by date with the newest at the top. If necessary, enlarge the window so that all of the contents are showing.

Follow the instructions in this support article under the heading "Take a screenshot of a window." An image file with a name beginning in "Screen Shot" should be saved to the Desktop. Open the screenshot and make sure it's readable. If not, capture a smaller part of the screen showing only what needs to be shown.

Start a reply to this message. Drag the image file into the editing window to upload it. You can also include text in the reply.

Leave the folder open for now.

Step 2

Do as in Step 1 with this line:

/Library/LaunchAgents

The folder that may open will have the same name, but is not the same, as the one in Step 1. As in that step, the folder may not exist.

Step 3

Repeat with this line:

/Library/LaunchDaemons

This time the folder will be named "LaunchDaemons."

Step 4

Open the Safari preferences window and select the Extensions tab. If any extensions are listed, post a screenshot. If there are no extensions, or if you can't launch Safari, skip this step.

Step 5

If you use the Firefox or Chrome browser, open its extension list and do as in Step 4.

Mar 21, 2016 5:23 AM in response to Koppa2000

You installed the "mediahm" trojan.

Please back up all data before continuing.

1. Delete item #1 in the screenshot.

Log out or restart the computer.

2. From the Safari menu bar, select

Safari Preferences... Extensions

Uninstall all extensions you don't know you need. If in doubt, remove all of them. None is required for normal operation. Do the equivalent in the Chrome and Firefox browsers, if you use either of those.

3. Reset the home page in each of your browsers, if it was changed. In Safari, first load the home page you want, then select

Safari Preferences... General

and click

Set to Current Page

dmg installer Virus?

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