: Indicates the link is intended to activate a specific filter or lens overlay. : Stands for Campaign ID
: The string following "SCFILTER" is a unique ID generated from the card’s Answer to Reset (ATR) string.
Thus, the value SCFILTER\CID_87d25e32ac0d4ef0b1e0502c6b7dfb77 is not a generic string—it is the .
While the SC Filter with CID87D25E32AC0D4EF0B1E0502C6B7DFB77 represents a significant advancement in content filtering technology, there are challenges to be addressed:
This technical guide breaks down the core mechanics of the scfilter architecture, explores why this specific string appears in the Windows Device Manager, and outlines exact, actionable steps to resolve missing driver errors associated with it. Understanding the Architecture: What is scfilter ? scfilter cid87d25e32ac0d4ef0b1e0502c6b7dfb77
Are you seeing this ID in a or as part of a malware scan report?
This alert is rarely an indication of hardware failure. Instead, it signifies that Windows Update does not possess a specific vendor-supplied minidriver matching that exact GUID sequence. If the token functions correctly inside third-party middleware (like ActivClient, SafeNet, or Charismathics), this warning is benign but aesthetically disruptive to clean system deployments. Step-by-Step Resolution Strategies Method 1: Repairing the scfilter Service Startup About Smart Card Minidriver Filter Driver(SCFILTER) - NTDEV
Whenever a physical smart card (such as an enterprise identity badge, yubikey, or government CAC) is slotted into a hardware terminal, Windows queries the device ID through the Microsoft Learn Smart Card Discovery Process to map out how software will communicate with the secure element. Typical Technical Specifications Specification Details Smart Card / Generic Smart Card Service File %SystemRoot%\System32\DRIVERS\scfilter.sys Registry Path
Here’s why:
How to investigate (ordered, minimal friction first)
Kaspersky, for example, uses its own for network packet interception—a completely different driver with a different purpose.
If you are seeing this as an "Unknown Device" in Device Manager, you may need to install the specific software provided by your smart card issuer (such as a bank or employer) to resolve the error. Are you seeing this ID as a security alert "Unknown Device" in your system settings? scfilter.sys - Microsoft Q&A
Windows sends a "Get Data" query to the card. The card responds with the raw bytes that form the 87D25E32... string. : Indicates the link is intended to activate
To see what local setting corresponds to this ID:
: The reader successfully powers the card chip and pulls the ATR string.
The SCFILTER driver is a legitimate, kernel-mode system driver provided by Microsoft, integral to the Windows Plug and Play (PnP) subsystem.