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CLSID

CLSID

(also Class ID)

CLSID definition

A CLSID is a serial number that represents a globally unique identifier for any application component in Windows. All registry entries for an application component have the registry key HKEY_CLASSES_ROOT\CLSID\{CLSID value}. The CLSID can also be used in Windows technical support scams (known as CLSID scams).

How scammers trick users

1. A victim receives a call claiming to be from Microsoft.
2. The caller says there’s a problem with the user’s computer (e.g., malware’s been detected, and unauthorized people are trying to gain access).
3. The caller tells the user they need to access the computer immediately to solve this problem.
4. They often quote a number, saying it is a unique ID only the victim’s computer has.
5. To convince the user they’re telling the truth, the scammers ask the victim to bring up a Command Prompt window, type in ASSOC, and hit “Enter.”
6. The scammers then ask the victim to find the CLSID number, saying it is the victim’s computer’s unique number. However, the CLSID number is not unique to every device – it is universal. Finally, the scammer asks for access to the victim’s computer (e.g., TeamViewer).