While there are many things that could be done to further improve this app, this app is currently not maintained. This means:
- We assess the main functionality as done
- We are not updating this app for future releases
- We are welcoming anyone who would like to take over this app, reach out in this issue: nextcloud#144
We would be more than excited, if you would like to collaborate with us. We would love to welcome co-maintainers.
If there is a strong business case for any development of this app, we will consider your wishes for our roadmap. Please contact your account manager to talk about the possibilities.
This app prevents the Nextcloud Sync clients from uploading files with known ransomware file endings.
When a known sync client is uploading a file with a file name matching the pattern of a ransomware (see this list of patterns), uploading of the file is blocked.
The user receives a notification with 2 options:
The file “foobar.txt” you tried to upload matches the naming pattern of a ransomware/virus “*.txt”. If you are sure that your device is not affected, you can temporarily disable the protection. Otherwise you can request help from your admin, so they reach out to you.
[ Pause protection ] [ I need help! ]
If you want to exclude the problematic pattern, you can copy it from this notification and ask your admin to add it to the exclude list. Hint: You can find the apps admin settings in the security tab of your Nextcloud instance. Admins can also see the pattern in the log when it is set to level Warning or lower.
If the user presses "I need help!" admins of the instance receive the following notification:
[ I will help ]
Pressing the button will delete the notification for all administrators.
After 5 "infected" uploads within 30 minutes, the clients of the user get blocked automatically to prevent further damage to the data. After the problem has been solved, the clients can be re-allowed in the personal settings of the user.
Configuration is managed on the Settings » Security page under the heading Ransomware protection.
You can choose to ignore extensions from the resources/extensions.txt file by entering the pattern into the 'Exclude extension patterns' field. You must enter patterns exactly as found in the extensions.txt file; entering something that is not a line in that file has no effect.
Example: if you entered .lock
in the Exclude extension patterns configuration field, then files that end in .lock
will be allowed to sync without suspicion. i.e. you will no longer be protected from attacks that rename/create files called <anything>.lock
.
You can also choose to use 'Additional extension patterns'.
Example: if you entered the pattern .oh-no
then any files that end with .oh-no
will be considered suspicious and blocked. Regular expressions are supported here, identified by patterns that begin with ^
or end with $
(or both), so you are not limited to files ending with a certain string. The pattern ^.*-evil-ha-ha-
would match any file names with -evil-ha-ha-
anywhere in their name.
When compiling the list of patterns, first the extensions.txt is loaded, then exclusions are removed, then additions added. This is an important feature as it allows specific exceptions to be made for certain files.
Example: Say your files include some composer.lock
and package.lock
files (these are common files in programming projects) and you wish to allow these to sync, but you don't want to allow any other .lock
files, as that is a commonly used extension by ransomware. You can achieve this by:
- Add
.lock
to the Exclude extension patterns configuration field. This will remove protection for .lock files, but then... - Add the regular expression
(?<!composer|package)\.lock$
to the Additional extension patterns configuration field. This pattern matches all.lock
exceptcomposer.lock
andpackage.lock
, so will allow those files to be uploaded but still block other files ending in.lock
Typically ransomware will leave note files (e.g. "you've been hacked, here's how to pay me to get your files back..."). The ransomware protection app can look out for these note files based on their file names see resources/notes.txt. The Include note files with non-obvious names option adds in an additional file of patterns. These additional files are rarely used in a general office files environment, but are fairly common in other sectors, so review these for your environment before checking this option.