Ad tech firm Optimizely has confirmed that threat actors accessed certain internal business systems through a sophisticated voice phishing (vishing) attack. The incident, the company told SecurityWeek, was immediately contained, the affected systems were secured, and the unauthorized access was terminated. “The threat actor gained access to Optimizely’s systems through a sophisticated voice-phishing attack, but was unable to escalate privileges, install software, or create any backdoors in the Optimizely environment,” the company said. Optimizely says it has no evidence of any sensitive customer data or personal information being compromised in the attack, but has proactively notified its customers of the incident. The company said the incident did not disrupt its operations and confirmed…