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Windows Defender Detected Citrix Services as Malware

Windows Defender has caused problems for some Citrix customers after deleting two services incorrectly detected as malware.

Windows Defender has caused problems for some Citrix customers after deleting two services incorrectly detected as malware.

The problem appears to be caused by the KB2267602 update. Windows Defender users who installed the update may have had their Citrix Broker and HighAvailability services on Delivery Controllers and Cloud Connectors deleted after they were erroneously detected as a trojan.

Windows Defender detects Citrix components as malware - Photo credits @CemBALIK

According to Citrix, impacted users may notice that the Broker service is no longer available in the Services console, that the BrokerService.exe file is missing from the Program Files folder, and an error saying that the Broker service could not be contacted.

Microsoft has released antivirus definition update 1.321.1341.0 to address the problem and Citrix has provided instructions on how to remove the buggy update and install the new one.

Citrix has also shared workarounds that can be used to restore impacted files and prevent Windows Defender from detecting them as malware.

Citrix earlier this week urged customers of its Endpoint Management (CEM) product, which is also known as XenMobile, to immediately install patches for multiple serious vulnerabilities. The flaws can be used to gain administrative privileges to affected systems, and the vendor expects hackers to quickly start exploiting them.

Related: Microsoft Rushes to Fix Bug That Broke Windows Defender Scans

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Related: Users Unable to Log on to Windows Due to McAfee Update

Related: Microsoft Pulls UEFI-Related Windows Update After Users Report Problems

Related: Symantec Endpoint Protection Update Causes Many Devices to Crash

Written By

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

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