US warns of looming Iranian cyber threat to US networks and extremist violence after strikes

The US Department of Homeland Security (DHS) issued a National Terrorism Advisory System (NTAS) bulletin on Sunday (June 22) warning of a heightened threat environment within the United States due to the ongoing Iran-Israel conflict and increasing anti-US sentiment in the region.

The bulletin, effective through September 22, 2025, highlights a growing concern over both cyber and physical attacks, particularly from Iranian-linked actors and ideologically motivated extremists operating domestically.

According to DHS, pro-Iranian hacktivists and cyber actors affiliated with the Iranian government are likely to increase low-level cyber attacks targeting vulnerable US networks and infrastructure. These efforts are seen as retaliation against US support for Israel.

The bulletin also warns of a potential escalation if Iranian religious leadership were to issue a formal call to violence, which could incite supporters in the US to commit acts of terror independently.

Iran’s historical targeting of US officials

The advisory notes that Iran maintains a long-standing desire to target US government officials. While multiple Iranian-backed plots have been disrupted in recent years, the threat of targeted violence remains active.

Extremism fueled by anti-semitism and conflict

DHS reported that several recent domestic attacks have been motivated by anti-Semitic or anti-Israel sentiment. The current conflict between Israel and Iran may further fuel such extremist ideologies, potentially leading to additional violence within the US against perceived Jewish or pro-Israel targets.

Foreign terrorist organisations—including Hamas, Hezbollah, the Houthis, and the Popular Front for the Liberation of Palestine—have released public statements calling for violence against US assets and personnel, adding to the urgency of the threat.