Recover computers from a deny execute everything policy

Owned by Anonymous
Last updated: Dec 15, 2015 by Mike Murphy
2 min read

Issue

This document tells you how to recover computers that have been locked out due to an improper manually created deny execute policy.

Solution

1. Disable the policy

Disable the manually created deny execute policy that has resulted in locking out computers.

2. Update affected computers

You can update affected computers by running a task via the Arellia Security Manager Console, or by manually restarting the affected computer(s).

Run a task

If you're still able to log into the affected computer, then you can run a task from the Security Manager Console to update the computer by doing the following steps:

  1. Click the Tasks tab.
  2. In the file library in the left pane, navigate to Jobs and Tasks > Client Tasks.
  3. Click Update Applicable Policies.
  4. In the right pane under Task Status, click Run Now.
  5. In the Run Task Now dialog box under Input Parameters, next to ResourceIds target all computers or only the affected computers.
  6. Click Run Task.

Perform a configuration update on each of the affected endpoints by creating a new Update Client Configuration Task and schedule it to run immediately on all computers, or on the computers that are known to have been affected by the deny execute policy.

Manual Update

If you cannot log into the affected computer, then you have to update the computer manually by doing the following steps:

  1. Restart the affected computer(s) in safe mode. (For details about starting in safe mode, go to Start your computer in safe mode.)
  2. In the Control Panel open Administrator Tools > Services. 
  3. Right-click Arellia Application Control and click Properties. 
  4. Change the Startup Type to Disabled 
  5. Click OK

  6. Restart the computer. 

  7. Go to the Control Panel again and open Administrator Tools > Services.
  8. Change the Arellia Application Control Startup Type to Automatic. 

More information on how to configure blacklisting policies

Additional Info

A manually created blacklisting or deny execute policy that has no application targets will apply to all programs and services and prevent them from running on an end-user's machine. If a new deny execute policy is created and enabled with out limiting the application target scope of the policy or is not being used with a proper whitelist, the bad blacklist policy will get rolled out and begin denying execution of all applications. This includes userinit.exe which will prevent users from logging in after a reboot. Those computers will act as if they are frozen because no new processes can get created.

Blacklisting best practices