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Terminal tricks for defeating adware

So, your browser is acting up, redirecting you to scamsites, offers for MacKeeper and Mac Cleaner and other unwanted software. You have what is technically known as ‘an adware’ infection. It’s not a virus, it’s not a ‘trojan’ and it’s not a ‘worm’, but it is a nuisance and may well be associated with any of the above. What to do?

Here’s 10 Terminal tricks you can use to help identify and remove adware items. It won’t cover every situation: adware mutates faster than a flu virus on amphetamines, but it will catch 90% of the cases currently out there. For the ones it doesn’t, see the ‘Getting Help’ section at the end of this post.

I’m going to split this up into two phases, ‘Gathering Information’ and ‘Dealing with the Results’. After explaining the first half-dozen commands individually, I’ll then give you one ‘master’ or ‘mother’ command which combines them into a single execution, but you should read through the explanations first so that you know what you’re doing and what to expect.

Gathering Info
First, most adware wants to persist on your mac across logins and restarts, and that means it has to put an executable somewhere where macOS will look on start up. One place most users should be familiar with and check first is the Login Items in System Preferences ‘Users & Groups’ pane. A lot of adware will insert itself there for good measure, but most will almost certainly be in other, trickier to find places.

This is where our first Terminal trick comes in. This Terminal trick will output the contents of the main locations where adware typically hides:

1. List the contents of your Launch* folders:


ls -alF /Lib*/Launch*/ ~/Lib*/Launch*/


That’ll output the contents of three different directories, /Library/LaunchAgents, /Library/LaunchDaemons, and ~/Library/LaunchAgents. If you’re planning on getting help by publishing the results in a public forum like Apple Support Communities, then you might want to use this version, which will scrub your username out of the results:

2. Same trick, redacting personal info:


w=`id -un`;ls -alF /Lib*/Launch*/ ~/Lib*/Launch*/ | sed "s@$w@[redacted]@g"


The output of that command will have a load of files with names like ‘com.company.filename.plist’. To give you an example here’s what mine outputs (note, none of these are adware files; unsurprisingly, my Mac is adware free!).

Slipping a shell script into the /etc/ directory is a common adware trick, so let’s also run this one, which will output any files in /etc/ that have the .sh shell script extension:

3. Find shell scripts in /etc/:


ls -alF /etc/*.sh


(this one won’t contain your user name, so we don’t need to redact anything).

A lot of adware persists by running sneaky little AppleScripts from a shell script. We can detect if any of these are at work with this little spell:

4. List osascript processes targeting your browser:


ps -axo ppid,pid,command | grep 'osascript -e global' | egrep -i "if is_Firefox_running|if is_Safari_running|if is_Chrome_running" | grep -v "grep" | grep -v ' 1 ' | awk '{ print $1, $2}'


All this command outputs is two numbers, perhaps like this:

7783 7792
7783 7825
8978 8987

We’ll discuss what to do with those in the ‘Dealing with Results’ section below.

Next, we want to see what processes are actually running in the background. This will both confirm and possibly add to information we collected earlier. To do this, we need a little trick which looks like the same command twice, but which in fact operates on two different lists of processes:

5. List loaded background processes:


w=`id -un`; r="s@$w@[redacted]@g"; launchctl list | grep -v apple | sed "$r"; sudo launchctl list | grep -v apple | sed "$r"; sudo -K


When you run this one, a list of processes will be output, and then you’ll be asked to supply an Admin password on the command line (where even the key presses won’t be visible when you type). Supply the password and a second list will be produced. We will want to examine both later.

A file name common to a widespread family of adware is rec_script.sh, and this can be hidden anywhere in the user or local Library folders, so let’s run this one, too (here we will add the redacting again in case you’re posting the results in a public forum). You’ll need to supply an admin password for this though:

6. Find a common adware executable:


w=`id -un`; sudo find /Library ~/Library -name "*rec_script.sh*" | sed "s@$w@[redacted]@g"; sudo -K


This one may take a couple of seconds to complete.

That concludes the first step of our info gathering stage, but for convenience, I’m going give you them all again concatenated into one, single ‘mother of all commands’ 😀 string. Even more conveniently, I’ve added code to output the results to a text file on your Desktop, called ‘adware_search.txt’, so after running the code below go look for ~/Desktop/adware_search.txt in Finder. If you’re posting to a public forum, it’s much easier to copy and paste the results from the text editor rather than from Terminal.

TL;DR
If you triple-click anywhere in the block of code below, you can copy and paste the whole block into Terminal and execute all of the commands given above in one fell swoop. Remember you’ll need a password.

7. The ‘Mother’ of all the above:


w=`id -un`; r="s@$w@[redacted]@g"; f="/Users/"$w"/Desktop/adware_search.txt"; ls -alF /Lib*/Launch*/ ~/Lib*/Launch*/ /Users/Shared /usr/local/bin | sed "$r" >> "$f"; printf "\n\n/etc:\n" >> "$f";ls -alF /etc/*.sh 2>/dev/null >> "$f"; printf "\n\n# osacript processes:\n" >> "$f"; ps -axo ppid,pid,command | grep 'osascript -e global' | egrep -i "if is_Firefox_running|if is_Safari_running|if is_Chrome_running" | grep -v "grep" | grep -v ' 1 ' | awk '{ print $1, $2}' | sed "$r" >> "$f"; printf "\n\n# User launchd:\n" >> "$f"; launchctl list | grep -v apple | sed "$r" >> "$f"; printf "\n\n# Root launchd:\n" >> "$f"; sudo launchctl list | grep -v apple | sed "$r" >> "$f"; printf "\n\n# Find rec_script.sh:\n" >> "$f"; sudo find /Library ~/Library -name "*rec_script.sh*" | sed "$r" >> "$f"; sudo -K


Interlude: Playing Safe
Before we move on to dealing with the results, I want to stress that you don’t want to be deleting files that you’re not sure of. Good practice is to move files to a temporary Quarantine folder, or at least move them to but don’t empty the Trash.

Even better practice is to make sure you have an up-to-date, bootable backup disk as well as a Time Machine backup, so that you can easily recover your system if you make a mistake and delete something you shouldn’t.

Dealing with the results
Looking at the output of the first Terminal command given above (Trick 1 or 2), how can you tell which are good and which are bad? In a lot of cases, you’ll recognise the app or developer name. TunnelBear, for example. “Sure, yeah, I’ve got that” and so on. Others, however, will look and sound weird, like these (all genuine adware file names):

com.glutting_Panagia.plist
com.pPHGASlN.plist
com.phellonic.plist

Google anything you’re not sure of, and see if it’s already been identified as adware. See ‘Getting Help’ at the end of this post if you’re not sure.

Walking up & down the tree
Assuming you’ve found some candidates for removal, the next job is to find the parent and child processes associated with each. We do that with a couple more Terminal tricks.

For the first one, we want to find any process that contains the same name as our suspected adware. For each suspect, take the unique part of the name for your search term. With this one we can put all our candidates in one command like so:

8. Search for your target’s family members:


w=`id -un`; ps -axo ppid,pid,command | egrep -i "glutting_Panagia| pPHGASlN | phellonic" | grep -v ' 1 ' | grep -v grep | sed "s@$w@[redacted]@g"


Note the part after egrep -i that’s inside quote marks. Each search term is separated between a vertical bar, aka the pipe character. Note that the terms themselves are not inside quote marks individually. One pair of double-quote marks is used to encapsulate all terms.

So to use the command above replace “glutting_Panagia| pPHGASlN | phellonic” with “search term 1 | search term 2 | search term 3”, where ‘search term n’ is your search term. Of course, you can have more or less than three search terms. Just add or remove as required.

When you examine the results, so long as the first number is not ‘1’ (it shouldn’t be if you executed the command correctly, as all those should have been excluded), follow the file path shown under the ‘Command’ column using either Finder or the Terminal. If you’re sure you’ve found a baddie, send it to the Trash or your quarantine folder! If you’re not sure, see ‘Getting Help’ below.

You will need to construct and run the next command separately for each suspect. The output will give you the path to the binary being executed by the plist. In many cases, you’ll have already found that from the previous commands, but in some cases – particularly if the plist has failed for some reason or if the binary isn’t running when you do your search – it won’t. This one’s the trickiest because you’re going to have to construct most of it yourself. Here’s an example (this is actually a legitimate file, but it will serve for our purposes):

cat /Library/LaunchAgents/com.razer.rzupdater.plist | grep -iA3 program

Let’s look at how that command is structured:

9. Find more children:


cat [path to file] | grep -iA3 program


You get the ‘path to file’ part from the results of your /Library/Launch* searches, and there’s no harm in practising this one on good files to get used to the output. For each item you search, it should return something that looks like this:

Here we see the path to the executable that the plist is launching. If this were a bad guy, I’d be straight over there to send him where he belongs, too.

After working through all your suspects with Trick 8, now take a look at the results of the command to output shell script file names from /etc/ (Trick 3). If there were any results at all (hopefully there wasn’t), you’re going to have to open that file in a text editor and determine whether it is malicious or not. This is the hardest part for the novice, because there’s certainly plenty of reasons to have a shell script in /etc/ depending on what 3rd party software you’re running. I can only repeat here what I have said above: see the ‘Getting Help’ section below if in any doubt.

Next, let’s take a look at the results for the osascript processes (Trick 4). Hopefully, you got no results, but if you had two sets of numbers outputted like this:

7783 7792

then the first number is the parent process ID, and the second number is the child ID. We want to find and eliminate both the parent (again, so long as this number is not ‘1’) and the child.

Take the first number and execute this in Terminal

10. More parents on the loose:


ps [number]


Take a note of the path that’s shown and ensure it doesn’t belong to a legitimate app that you recognise. Again, if in doubt, ask Google, or see ‘Getting Help’ below.

Now, do the same with the second number, the child process. Work through however many numbers were output, ‘quarantining’ as you go.

Almost there! Take a look at the output of the two launchd lists (Trick 5). You should have a good idea by now which ones are suspect and which are OK. You may have found the paths to any suspicious ones already, but if not, we’ll use the same command as we just used with the osascript processes. Here’s the output on my machine of the Trick 5 command (all legitimate) for comparison:

We’re only interested in the first number (the second one is status code). For any suspicious process, take the first number shown in the list, and use the Trick 10 command on these to find the parent file path (you know what to do with the ones that aren’t legitimate!).

If there is only a ‘-‘ dash instead of a number, it means that process is or was loaded but is not currently running. That dash may or may not be followed by another number that is not ‘0’. That number is just an error code and isn’t really relevant to us here. For any of your suspects that have failed like that, hopefully the info you gathered earlier will give you some clues (if not, see ‘Getting Help’ next).

Finally, anything found in the ‘find’ command (Trick 6) is almost certainly malware. Of course, be mindful that it’s entirely possible a legit’ script could accidentally have a name clash and be called rec_script.sh, but it’s highly unlikely and definitely should be examined closely. Also, if you see that the path is within an application bundle like this …Contents/MacOS/rec_script.sh, don’t hesitate to pull the trigger on that one.

Getting Help
I want to repeat that doing this safely and effectively takes practice and experience, and you should in no way be surprised that, if you don’t have that experience, you’re not sure whether something you’re looking at is good or bad, or that you go through all of this and still can’t find the problem. There’s some fairly obscure ways that adware and other malware can infest and persist on your mac that only experts will be able to advise you on. Throughout this post I’ve glossed over a few situations where you’ll draw a blank, and that’s because most of the other techniques for spotting malware require that experience.

To ameliorate this, I wrote an app called DetectX Swift to deal with this and many other things, and you can download it and use it without any requirement to pay. You can also use it to get personal, free-of-charge, help from me through the Help > Report a Problem to Sqwarq Support if your troubles persist.

Let me be clear why I don’t charge for this personal service: the payoff for me is I get to improve my app’s heuristics from what I learn about infections that DetectX doesn’t automatically detect. All information is kept strictly confidential and I do not sell or use your email address or other information for any marketing purposes whatsoever.

If you want to read more about me, also see the about page on DetectX’s parent site, Sqwarq.com.

Happy hunting! 🙂

 

FastTasks version 1.18 released! 💥

FastTasks v.118

I’ve just posted an incremental update to my free system utility, FastTasks. The update fixes a bottleneck in the launch code that caused FastTasks to take excessively long to load. I’ve also added the System Uptime, which you can also refresh with the new keyboard shortcut, ‘command-U’.

FastTasks saves you having to role up your sleeves and get mired in the exotic world of Terminal’s command line for a number of common tasks. FastTasks v1.18 offers you system info down the left side of the panel, all of which can be updated by the shortcuts displayed on the panel, and access to some common Terminal commands on the right.

If you haven’t tried FastTasks yet (or got tired of the slow launch times with the old version), this is a great time to grab a free copy of v1.18 as I’ll soon be replacing the app by FastTasks 2.0, a paid-for app with a whole new interface and extra functions. Nevertheless, support for FastTasks 1 will continue and bug fixes will still be forthcoming as necessary. Grab it while you can, folks! 🙂

Download FastTasks v1.18 from here…

Note: FastTasks requires OS X 10.6.8 or higher


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