1. Stuxnet worm: Stuxnet is a malicious computer worm that targeted industrial control systems (ICS) in vital sectors of the economy, including nuclear power plants. It was spread by exploiting vulnerabilities in Windows-based SCADA systems, such as DCS, RTU, and HMI, and caused significant damage to Iranian nuclear facilities.

2. Triton attack: the Triton malware targeted SCADA systems used in public infrastructure, such as power plants and critical manufacturing facilities, through a vulnerability in Schneider Electric's Triconex TriStation protocol. This attack used a combination of non-human intervention, DCS, RTU, and HMI to create an unexpected, shut-down mode in target sites.

3. Havex attack: The Havex malware targeted SCADA systems primarily through phishing attacks sent via email, exploiting vulnerabilities in the DCS, RTU, and HMI. The attackers used the payload to collect huge amounts of data from SCADA systems, potentially allowing them to completely determine the architecture of an ICS system.

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