Cyberattack sends false radiation and chemical alerts to apps in Kyiv and Moscow

Late Sunday evening, users in Kyiv opened their phones to find false warnings that radiation levels had spiked dangerously in the capital. The digital intrusion struck emergency alert applications in both Ukraine and Russia, sending mixed signals of chemical threats and public disturbances to thousands of residents during a period of heightened tension.

Ukraine’s air raid alert channel confirmed the breach via a Telegram post late Sunday. The officials stated that unauthorized parties had interfered with the app’s operation, prompting a temporary suspension of the service. The false notifications were written in English with spelling and grammatical errors, as well as in a mix of Russian and Ukrainian. The alerts claimed high radiation levels and a chemical threat existed in Kyiv, information that did not match physical readings.

A Russian Telegram channel called Mash, which has links to Russian security services, reported that the hacking group Hitcore claimed responsibility for the attack. One of the false posts mentioned the group by name. Mash said it spoke to representatives of Hitcore, who asserted they conducted the operation. The claim had not been independently verified by other agencies or security experts as of Monday.

Ukrainian authorities restored the app’s functionality overnight. The state-run Center for Countering Disinformation urged citizens to monitor emergency channels on social media and rely on physical alerts while the cyberattack was addressed. Yurii Ihnat, a spokesman for Ukraine’s air force command, told the private 1+1 television network that the cyberattack had no impact on Ukraine’s security and defense operations. He noted that the app is separate from military command systems and that the air force continues to report real-time threats through independent communication channels, including popular social media platforms.

In Russia, officials announced on Monday that hackers had gained access to the Russian Emergency Ministry's mobile app. The ministry did not name the specific group responsible for the intrusion. In a statement, the ministry reassured the public that the wider alert system was working normally. It clarified that the mobile app acts as a supplementary service alongside alerts shared through SMS messages, media broadcasts, and municipal sirens and loudspeakers.

The cyberattack occurred while a limited ceasefire in the Kherson region was concluding. Ukrainian authorities reported multiple Russian drone attacks early Monday, hours after the humanitarian ceasefire expired. The localized ceasefire ended at midnight at the start of Monday. The brief pause in fighting was tied to a humanitarian aid mission in the Russian-occupied city of Oleshky. The ceasefire, which began on October 27, marked a notable truce between Kyiv and Moscow since Russia’s full-scale invasion began nearly five years ago.

The White House stated that U.S. first lady Melania Trump helped broker the limited truce. Civilian negotiators from Russia and Ukraine also helped secure the pause. This arrangement allowed besieged residents of Oleshky to be evacuated in a rare joint operation that ended Saturday. An estimated 2,000 civilians were in Oleshky when the temporary truce took effect. They could evacuate to territory controlled by either Ukraine or Russia, or remain in the city with replenished food and medical supplies. Exact evacuation totals were withheld to protect those who stayed.

Ukraine’s general staff reported on Monday that Russia’s military had bolstered its drone defenses and replenished ammunition supplies in the area during the ceasefire. Elsewhere in Ukraine, emergency services reported that drone strikes injured 12 people in the eastern Kharkiv region. The strikes damaged a refrigeration facility, greenhouses, and residential buildings. Five people were also reported injured in the Black Sea port city of Odesa, where a warehouse was targeted and homes were damaged.

In the city of Kherson, a 62-year-old woman and a 73-year-old man were hospitalized with blast injuries early Monday. The city is located across the Dnipro River from Russian-occupied territory. The regional administration confirmed the injuries as part of the post-ceasefire drone attacks.

The disruption to digital alert systems forced both populations to revert to older methods of communication and verification. The incident added a layer of complexity to the ongoing conflict, where accurate information is often treated as a tactical asset. The restoration of the Ukrainian app and the Russian ministry's assurance of system stability marked the immediate end to the digital confusion.