Knowledge Center

FAQs for V2 DAT files
Technical Articles ID:   KB55986
Last Modified:  5/11/2018


McAfee V2 DAT Files
McAfee ExtraDAT files
McAfee Signed ExtraDAT files
McAfee Labs (AVERT)
McAfee DAT Reputation


This article is a consolidated list of common questions and answers and is mainly intended for users who are new to the product, but can be of use to all users.
DAT Reputation
Signed ExtraDAT

What are DAT files?
Virus definition or DAT files contain virus signatures and other information that McAfee anti-virus products use to protect your computer against existing and new potential threats. DAT files are released on a daily basis. We also release new DAT files when any threat is assessed by McAfee Labs to have a medium or higher risk. To ensure that your anti-virus software can protect your system or network against the latest threats, you must ensure you are using the most recent DAT files.

What products use DAT files?
The following products use the AV Scanning Engine and DAT files:  
  • Advanced Threat Defense
  • Email & Web Security (End of Life (EOL) March 31, 2017)
  • Email Gateway 
  • Endpoint Security
  • Endpoint Security for Mac
  • Management for Optimized Virtual Environments (MOVE)
  • SaaS Endpoint Protection
  • Security for Lotus Domino 
  • Security for Mac (EOL September 30, 2016)
  • Security for SharePoint (PortalShield)
  • SuperDAT Manager
  • VirusScan Command Line Scanner
  • VirusScan Enterprise
  • VirusScan Enterprise for Linux
  • VirusScan Enterprise for Storage
  • VirusScan for Mac
  • Web Gateway

What integrity and validity checks are performed on the DAT files to ensure they are not tampered with?
The DAT files are encrypted and then compressed and signed when they are compiled. The Antivirus Engine performs a signature verification on the DATs as an integrity check during initialization and will not load them if they have been modified. The products that utilize the Engine in turn verify the integrity of the Engine by checking whether the digital certificate used to sign the Engine is valid.

Does the DAT perform any proactive detection for scanning of malformed archives?
McAfee products have the ability to handle specific types of malformed archives which cause the Scan Engine to be unable to scan within the archive by providing proactive detection of malformed archives within our DAT files. This enables the products to detect the presence of a bad archive without having to open it. Detection for these is reported as Malformed Archive.

As more testing is done around the various types of malformed archives that can be created, McAfee will continue to refine our detection techniques and update the driver in the DAT files. McAfee continues to focus on ensuring that customers receive maximum protection and providing a rapid response to potential vulnerabilities.

Why does McAfee Labs release DAT files on a daily basis?
There has been an exponential rise in the number, propagation rate, and prevalence of new threats. The same applies to the number of virus submissions, the rate of new malware development, and the number of emergency DAT releases. The growing number and variety of threats make it vital that you update your DAT files on a daily basis.

Can there be more than one DAT release per day?
McAfee Labs releases at least one DAT file every day of the year, with the exception of January 1 and December 25. If necessary, emergency DAT files will be issued on these days.

At what time during the day will the daily DAT files be made available?
The daily DAT files are generally available by 19:00 (UTC/GMT). However, if a new threat warrants this, daily DAT files may be released earlier. Under some circumstances daily DAT releases may be delayed. To receive alerts regarding delays or important notifications, subscribe to the Support Notification Service (SNS). For SNS details, see article KB67828.

NOTE: For local time conversion, see http://www.worldtimeserver.com/current_time_in_UTC.aspx or a similar site.

For what time should I schedule a daily automatic update of my system with the daily DAT files?
McAfee recommends scheduling a daily pull task within a 4-6 hour interval from the time the daily DAT files are made available to the source repository. This allows enough time for the DAT file to be replicated on all McAfee servers globally. See your ePolicy Orchestrator Product Guide for details.
For a full list of product documents, go to the ServicePortal at: http://support.mcafee.com. Click Knowledge Center, and select Product Documentation from the Knowledge Base list.

Where can I find the latest DAT files?
The latest DAT files are available from the Updates page in XDAT and SDAT format at: http://www.mcafee.com/apps/downloads/security-updates/security-updates.aspx. This site also provides access to Beta DAT files.

What is the difference between daily DAT files and Beta DAT files?
Daily DAT files are released once per day and go through a full QA cycle. Beta DAT files are produced hourly and receive only limited false positive testing. McAfee recommends you use the daily DAT files for desktop deployment, and the Beta DAT files for high-risk computers and perimeter products such as GroupShield.

For more information, see http://www.mcafee.com/apps/mcafee-labs/beta/dat-file-updates.aspx?region=us.

What is the difference between Normal DAT files and Runtime DAT files?
Each has its own advantage:  
  • Normal DAT files The normal copy of DAT files are much simpler in format with optimization designed for downloads of daily incremental files (signatures). It is a priority for downloading the normal DAT updates that as little bandwidth as possible be used, but it is not well optimized for local performance.
    Advantage: Faster download
  • Runtime DAT files
    The runtime DAT is optimized for high local performance. It is a rebuild of the normal DAT files, so that the memory and CPU resources needed to operate are balanced for best performance.
    Advantage: Faster system
Under what circumstances do emergency DAT releases happen?
Outbreaks can require emergency releases. Daily releases generally ship around 19:00 GMT every day, but may be released earlier or later in the day if a new threat warrants this. When a daily DAT is released early to pre-empt a potential outbreak, there will generally be no second DAT release that day at the normally scheduled time, unless another emergency situation warrants one.

Where can I find the daily DAT Release Notes?
The daily DAT Release Notes are available at www.mcafee.com/apps/mcafee-labs/release-notes/datreadme.aspx?region=us.

In what format are the daily DAT Release Notes provided?
The daily DAT Release Notes are web-based and offer the option to be emailed (as a link) or printed.

When are the daily DAT Release Notes published?
The release notes are available approximately two hours after the release of the daily DAT.

NOTE: The daily DAT Release Notes were first published in the location mentioned above on September 24, 2012 with the release of DAT ID 6845.

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DAT Reputation 
What is DAT Reputation?
DAT Reputation is an endpoint technology that contacts the GTI Cloud prior to an endpoint DAT update. The call-back component checks the reputation of a DAT package before installing the update. Additionally, an endpoint safety pulse component runs periodically on a Microsoft Windows endpoint to check for potential product or operating system issues that have occurred since the installation of a DAT update package. Data collected from the endpoint safety pulse tests are transferred back to McAfee Labs and monitored for anomalies. If a significant problem is found with a DAT package after it has been released, it is marked as Blocked in the Cloud to prevent endpoints from installing the DAT.

Will McAfee still contact me via the Support Notification Service (SNS) if there is a problem found with the current DAT?
Yes. McAfee Incident Response procedures are invoked if a significant problem is found with a DAT. McAfee recommends that all corporate customers register for SNS.
To receive information about McAfee product updates, sign up for the Support Notification Service at https://sns.secure.mcafee.com/signup_login.

Which products are able to use DAT Reputation?
DAT Reputation is for all supported products on Microsoft Windows that update using a DAT. The minimum supported McAfee Agent (MA) version for DAT Reputation is MA 4.6.

What happens if my endpoints update via ePolicy Orchestrator?
The endpoints will call the GTI Cloud individually, in case a problematic DAT has already been downloaded to a local repository.

What are the system requirements for DAT Reputation?
DAT Reputation has been tested with Windows Vista and later. The recommended system requirements are:
  • Processor  
    Minimum: Pentium class processor
    Recommended: Pentium IV class processor or higher
  • Physical RAM  
    Minimum: 512 MB
    Recommended: 1 GB or greater

Where will the DAT Reputation files be installed?
DAT Reputation files are installed to the following locations:  

  • 64-bit computers: %programfiles(x86)%\common files\McAfee\DATReputation
  • 32-bit computers: %programfiles%\common files\McAfee\DATReputation
Where do I download DAT Reputation?
DAT Reputation is installed as part of a standard DAT update. Customers can electively download DATs containing DAT Reputation for approximately six months prior to AutoUpdate. The elective download period began on August 19, 2014.

New health check content might be added at a later date, if further diagnostic tests are required. Health check content will also be delivered as part of a standard DAT update. Customers are notified via SNS when new health check content is going to be deployed.

What will be the increase in download size when DAT Reputation is installed?
The update size will be approximately 1 MB, in addition to the size of the standard DAT content.

Will updates fail if my endpoints cannot connect to the GTI Cloud?
DAT Reputation will not block updates if the endpoint cannot make a connection to the GTI Cloud.

Will DAT Reputation work in an environment using proxy servers?
Yes, provided the endpoint is able to communicate on port 443 using SSL over TCP. The following proxy servers are supported:
  • Basic proxy
  • NTLM
  • LDAP
  • Proxy without Authentication (Transparent Proxy)
NOTE: Kerberos authentication is not currently supported.

Can DAT Reputation be configured to utilize GTI Proxy?
No, there are no current plans to introduce this functionality with GTI Proxy.

What type of data is collected when checking the DAT reputation?
The DAT version number and the DAT type (V2 or V3) are securely transmitted to verify the reputation of the DAT file. No additional information about the endpoint is uploaded.

What type of data is collected during the endpoint safety pulse health check?
The only data collected are the results of a small number of tests being run on the endpoint following a DAT download. These results contain data such as:  
  • Whether a test passed or failed.
  • Some metadata about the endpoint, such as the operating system name and version, the DAT and engine versions, and what product/versions are installed.
IMPORTANT: No personally identifiable information is collected or transmitted.

Why is this data collected?
This data helps McAfee ascertain whether the recently downloaded DAT is behaving as expected and is providing value to the security of your endpoint.

How frequently will the health check component run on an endpoint?
The health check component will run between six to eight times per day.

What size are the data packets sent for the DAT Reputation check and Health Check data?
Approximately 200 bytes of data for a reputation check, and between 1-2 kb of data are transferred per instance of health check data.

How will the Health Check data be encrypted and transferred?
The data will be encrypted using SSL and transferred using SSL over TCP, using port 443.

How will the health check data be stored?
The data will be stored and secured on McAfee’s backend databases.

Which domain does DAT Reputation connect to?
It connects to datreputation.gti.mcafee.com and datreputation.mcafee.com.

Will endpoints that cannot connect to the Internet try to use DAT Reputation?
Endpoints on closed or limited networks can be configured to disable the DAT Reputation check and endpoint safety pulse. However, in the unlikely case of a Bad DAT update, these computers must have their update tasks disabled by an administrator. An ePO extension will be provided for policy management and reporting. Customers with unmanaged endpoints can contact Technical Support for further information on how to configure DAT Reputation settings (for details, see the Related Information section below).

NOTE: McAfee does not recommend disabling DAT reputation unless absolutely necessary. 

Who should I contact if I have further questions or ideas for a future release of DAT Reputation?
Contact your local Technical Support representative (for details, see the Related Information section below).

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What is an XDAT?
This is an application that you can double-click to start from Windows. It shuts down any active anti-virus scans, services, and other memory-resident software components that might interfere with your updates. It then copies the new files to the required location and enables your anti-virus software to use the update immediately. XDAT files contain virus definitions without the Engine.

How do I recognize an XDAT file?
The file has a name in the format nnnnXDAT.EXE, where nnnn is the DAT version number. The daily XDAT file includes the DAT files plus an executable that installs them. Running an XDAT with non-Administrative privileges is not supported. For more information on XDAT files, see http://download.nai.com/products/datfiles/4.x/nai/readme.txt.

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What is an ExtraDAT file?
An ExtraDAT is a temporary definition file in response to malware that is not yet covered in the daily DAT files. The ExtraDAT is intended to provide emergency coverage until detection for the new malware can be added into the daily DAT files. You must apply an ExtraDAT to the infected system and any systems that could potentially be compromised.

What is a custom DAT package?
A custom DAT package is a temporary detection file created by McAfee Labs, containing the full production DATs and additional detections and cleaning for a new threat that is too complex to be addressed in an ExtraDAT. For how to use a custom DAT package, see KB76657.

Will an ED still be available when emergency releases happen?
Yes, ED files will still be available from McAfee Labs and will still be made available for download for threats that reach a medium-risk assessment or higher. Additionally, you will still receive an ED for any new samples submitted to McAfee Labs.

How safe are ED files?
ED files get released after limited testing and provides these with the sole purpose of addressing a specific threat. When you have to deploy an ED to more than a few nodes, McAfee recommends you test the ED on a subset of these nodes before deploying to all systems. After you have verified that there is no problem with the ED, you can deploy it to the remaining nodes.

How long can I use my ED file?
The standard expiration for an ED is thirty days, but this can vary. Detection in an ED automatically expires when the date embedded in the daily DAT files is the same as or later than the expiration date of the detection in the ED.

How do I get an ED file?
These files are provided directly by McAfee Labs in response to submitted malware. For instructions on how to submit malware samples, see KB68030.

How many ED files can I use?
Only one file can be active on a computer at any given time. You can combine multiple ED files to provide protection for multiple new threats. For detailed instructions, see KB68061.

How do I apply an ED?
To deploy and apply an ED file through ePolicy Orchestrator 4.x, see KB67602.
To apply an ED locally, refer to the following:  
  • For SaaS Endpoint Protection, see KB51459.
  • For Security for Microsoft Exchange 7.6, see KB76201.
  • For VirusScan Enterprise 8.x, see KB50642.

How does an ED relate to the daily DAT?
Detection in an ED takes precedence over detection in the standard DAT files. If the remediation method of an ED differs from that of the standard DAT, the method specified by the ED is used.

Why are ED files removed from a system, and what determines when an ED should be removed?
The removal of an expired ED is determined by comparing the expiration date of the detection in the ED to the date embedded in the applied DATs. This is done when the engine loads the DAT.
When the embedded date of the DATs is equal to or greater than the expiration date of the detection in the ED, the Engine will see the detection in the ED as expired.
Example: If today (9/11/2012) you are running 6829 (from 9/8/2012) and your ED expires on 9/9/2012, the Engine will continue to use the ED until the DATs are updated to 6830 (from 9/9/2012) even though today is 9/11/2012.

What do I do when an ED detects a virus but does not clean or repair files?
Refer to the VirusScan Enterprise ED checklist. For details, see KB54996.

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Signed ExtraDAT 
What is a Signed ExtraDAT (SED) file?
An SED has the portability of an ED and the comprehensive detection and cleaning functionality of a Beta and full DAT. The SED is designed for you to apply it without having to make changes to your infrastructure.

When is a SED sent?
A SED is only sent when there are cleaning limitations in the current ED solution, for example, when there is a need to have process ejection or parasitic file cleaning.

Why are SEDs not used all the time?
A SED is not sent when there are adequate capabilities in the ED solution. There may also be occasions where Beta DAT files are still required for full cleaning of a specific threat. The McAfee Labs Global Threat Response team advises on an individual basis what solution is best for you.

How can I see the difference between an SED and an ExtraDAT?
In addition to the added cleaning abilities, the SED file size is slightly larger than an ED because of the additional code it contains. The file names are identical (ExtraDAT), and concatenation works as normal.

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What are the CommonUpdater Repositories?
The following update sites are used by ePolicy Orchestrator:

FTP Sites
HTTP Sites
NOTE: You can use the following alternative update sites if you do not use ePolicy Orchestrator:

FTP Sites

HTTP Sites

What is the difference between the CommonUpdater and CommonUpdater2 sites?
The CommonUpdater2 download site does not have a copy of the DAT files in its root folder.

What are the benefits of the CommonUpdater2 download site
If you have no products installed that look for DAT content in the root directory of the site, selecting the CommonUpdater2 site offers bandwidth benefits because fewer files need to be replicated.

Can I use a direct IP address instead of DNS resolution for updating?
Hosting the DAT content requires hundreds of IP addresses for load balancing and high availability. These IP addresses are not static and their direct use is unsupported. For details, see KB54974.

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