Removed one deprecated alert from the Linux list

Author: memildin

articles/security-center/alerts-reference.md

@@ -37,7 +37,6 @@ Below the alerts table is a table describing the Azure Security Center kill chai
 ||<a name="alerts-linux"></a><h3>Linux machines</h3> [Further details and notes](security-center-alerts-iaas.md#linux-)||
 |**Process seen accessing the SSH authorized keys file in an unusual way**|An SSH authorized keys file has been accessed in a method similar to known malware campaigns. This access can indicate that an attacker is attempting to gain persistent access to a machine.|-|
 |**Detected Persistence Attempt**|Host data analysis has detected that a startup script for single-user mode has been installed.<br>Because it's rare that any legitimate process would be required to run in that mode, this might indicate that an attacker has added a malicious process to every run-level to guarantee persistence. |Persistence|
-|**Manipulation of scheduled tasks detected**|Host data analysis has detected possible manipulation of scheduled tasks. Attackers often add scheduled tasks to machines they've compromised to gain persistence.|Persistence|
 |**Suspicious file timestamp modification**|Host data analysis detected a suspicious timestamp modification. Attackers often copy timestamps from existing, legitimate files to new tools to avoid detection of these newly dropped files.|Persistence / DefenseEvasion|
 |**A new user was added to the sudoers group**|Host data analysis detected that a user was added to the sudoers group, which enables its members to run commands with high privileges.|PrivilegeEscalation|
 |**Process associated with digital currency mining detected**|Host data analysis detected the execution of a process that is normally associated with digital currency mining.|Exploitation / Execution|