Ukraine, Russia Report App Hacks Behind Fake Nuclear Alert Messages

Ukraine's air-raid warning app and Russia's own emergency alert system were both targeted by hackers over the weekend, officials in each country said, with the Ukrainian attack triggering false messages about radiation, chemical threats and street combat, according to NBC News.

The fake alerts hit phones in Ukraine starting around 10:45 p.m. Kyiv time Sunday, Nov. 1 (3:45 p.m. ET), NBC News reported. The timing fell just as a rare humanitarian ceasefire between Kyiv and Moscow expired, a coincidence that officials and outside observers say has raised fears of intensified fighting rather than a step toward broader peace.

What did the fake alerts actually say?

The messages told residents not to leave their homes because of a "radiation hazard," a "chemical threat" and ongoing "street fights," according to NBC News. One message, written in Russian, declared that all of Ukraine was under a nuclear alert. "Don't worry," the message added. "Oreshnik is in action" — a reference to Russia's nuclear-capable hypersonic missile, the outlet reported.

A translated screenshot of the alerts was circulated by Ukraine's Centre for Strategic Communication, which posted the image on X, according to NBC News. Ukraine's air force said shortly after the messages went out that the country's "Air Alert" app had likely been "compromised by the enemy," confirming there was no actual radiation threat and urging the public to remain calm, NBC News reported.

Who says they were behind the hack?

One of the fake messages referenced a Telegram channel called Hitcorecorp, according to NBC News. The pro-Kremlin Telegram channel Mash said it had spoken with the group and that it claimed responsibility for the intrusion, the outlet reported. NBC News said it could not independently verify who the group is or confirm it was actually responsible for sending the alerts.

The creators of the Air Alert app said in separate statements that "unauthorized third parties interfered with the operation of the app," forcing a temporary suspension of service, according to NBC News. The app's operators later described the incident as a "cyberattack" and said the service was being gradually restored, adding that the team was "carrying out additional measures" to secure the system, the outlet reported.

What happened with Russia's alert system?

Hours after Ukraine reported its app had been compromised, Russia said its own emergency alert system had also been hacked, according to NBC News. The dueling accusations arrived on the same day, each side pointing to a breach of the systems civilians depend on to learn of incoming danger.

Millions of Ukrainians use the Air Alert app and similar services to get advance warning of Russian missile and drone strikes, giving residents time to reach shelter before impacts, NBC News reported. That reliance is precisely what made Sunday's false alerts unsettling — the same channel ordinarily used to save lives was, for a window of time, pushing unverified claims of nuclear and chemical danger.

Why does the timing matter?

The hacks landed just as a rare humanitarian ceasefire between Ukraine and Russia came to an end, according to NBC News. Rather than signaling a path toward de-escalation, the breach and the alarming content of the fake messages raised concern among officials that fighting could intensify in the near term. NBC News did not report any confirmed link between the ceasefire's expiration and the cyberattack itself, and the identity of the attackers remains unconfirmed.

What to watch next

• Whether Ukrainian or Russian authorities formally attribute the intrusions to a specific state or non-state actor.
• Confirmation of Hitcorecorp's identity and whether independent researchers corroborate its claimed role.
• Updates from the Air Alert app's developers on when the service is fully restored and what security changes follow.
• Any shift in strike activity in the days after the humanitarian ceasefire's expiration.

Neither Ukrainian nor Russian officials, as quoted by NBC News, offered a timeline for a full security review of the affected alert systems. The episode underscores how emergency-notification infrastructure built for wartime civilian protection has itself become a target in the broader conflict.