Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Endpoint Security

Microsoft Rushes to Fix Bug That Broke Windows Defender Scans

Microsoft has rushed to fix a bug that prevented users from running a quick scan or a full system scan with Windows Defender.

Microsoft has rushed to fix a bug that prevented users from running a quick scan or a full system scan with Windows Defender.

Many users reported this week that after they installed the latest update for Windows Defender the security application would only scan a small number of files — reports say between 4 and 64 files.

Impacted individuals said the scans would simply end seconds after a Quick Scan or Full Scan was initiated. Custom scans, which allow users to manually select what they want to check, appear to work normally.

The issue impacts Windows Defender 4.18.1908.7 running on Windows 10, Windows 8.1 and Windows 7.

Users started complaining about the problem on Microsoft support forums and other websites a few days after Windows Defender 4.18.1908.7 was released. Microsoft immediately took action and released a fix within hours.

However, BornCity reported that while the scans now appear to work, scanning pauses a few times until all files are checked.

According to BornCity, the buggy Windows Defender update was meant to fix an issue related to the sfc /scannow command in Windows 10. This command uses the System File Checker tool to find and repair corrupt files, but an update released by Microsoft in July caused the repair feature to stop working.

UPDATE. Microsoft told SecurityWeek that it has now also addressed the issue that caused the scanning process to pause. The company said it only impacted a subset of customers.

Advertisement. Scroll to continue reading.

Microsoft also clarified that Windows Defender continued to provide automatic protection and users were not left exposed while the scanning bugs existed.

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

Related: Malwarebytes Delivers Buggy Update to Home, Enterprise Users

Related: Buggy ESET Update Blocks Many Websites

Written By

Eduard Kovacs (@EduardKovacs) is a managing 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.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Endpoint Security

Today, on January 10, 2023, Windows 7 Extended Security Updates (ESU) and Windows 8.1 have reached their end of support dates.

Application Security

Virtualization technology giant VMware on Tuesday shipped urgent updates to fix a trio of security problems in multiple software products, including a virtual machine...

Endpoint Security

Gigabyte has announced BIOS updates that remove a recently identified backdoor feature in hundreds of its motherboards.

Endpoint Security

Several major companies have published advisories in response to the Downfall vulnerability affecting Intel CPUs.

Application Security

Microsoft on Tuesday pushed a major Windows update to address a security feature bypass already exploited in global ransomware attacks.The operating system update, released...

CISO Strategy

Varied viewpoints as related security concepts take on similar traits create substantial confusion among security teams trying to evaluate and purchase security technologies.

Endpoint Security

The Zero Day Dilemma

Endpoint Security

When establishing visibility and security controls across endpoints, security professionals need to understand that each endpoint bears some or all responsibility for its own...