Department of Homeland Security spokesman Scott McConnell refused to explain if U.S. firms or infrastructure have been affected by the cyber attacks, but he said that the government is in communication with its worldwide partners and is ready to provide help to anyone who requests it, Efe news reported.
Experts also said this latest attack could heighten fears that companies may be more vulnerable to cyberattacks than suspected, potentially putting personal data at risk. The source of the attack is not yet clear.
According to cybersecurity experts surveyed by the newspaper, the virus is unlikely to be a version of the recent WannaCry ransomware, but a modification of the Petya virus that attacks hard drives and spreads through emailed links and then through internal networks. Both asked victims to pay Bitcoin to get their files back, and both use a similar flaw to spread through networks.
Numerous victims of Tuesday's cyber attack said their computers were blocked with a demand for $US300 ($395) worth of the Bitcoin crypto-currency to restore access to its files.
NYC subway station evacuated after smoke, loss of power
A student journalist tweets there was a train derailment near 125th. "It wasn't heavy smoke, but it was frightening", he said. Lhota said the emergency braking system on the train triggered, but it wasn't immediately clear why.
Cyber security firms scrambled to understand the scope and impact of the attacks, seeking to confirm suspicions hackers had leveraged the same type of NSA hacking tool exploited by WannaCry and to identify ways to stop the onslaught.
It also recalled a ransomware outbreak last month which hit more than 150 countries and a total of more than 200,000 victims with the WannaCry ransomware.
Therefore, it remains to be seen whether the patchwork was good enough or if the new ransomware was using the same vulnerabilities as WannaCry because not all people and organisations installed the Microsoft-issued patches.
"Petya spread via email spam with booby-trap@kkped (Microsoft) Office documents.The documents, once opened, will download and run the Petya installer and execute the Server Message Block (SMB) worm to spread to other computers", SingCERT said.
For advice from the Department of Homeland Security on how to avoid ransomware attacks, go here. "We stand ready to support any requests for assistance".
The attack struck at 2 p.m. local time, Ukraine's government says.
DU colleges release cut-off; highest 99.66% for Electronics
Admission to 54,000 undergraduate seats of various DU colleges received over 2.5 lakh applications, the report said. The situation is similar at other top colleges such as Sri Venkateswara College where the cut off for B.Com.
Ukrainian companies and government agencies seem to have been hit particularly hard.
Ukraine's National Bank said in a statement said that an "unknown virus" has caused banks "difficulties in serving clients and carrying out banking operations".
Officials at Ukraine's postal service and metro system in Kiev also reported hacking problems.
In Ukraine, networks of Borispol airport near Kyiv, as well as the government computer network, were said to be affected, with Ukrainian Deputy Prime Minister Pavlo Rozenko tweeting a picture of an error message on his screen.
The automatic radiation monitoring system at the Chernobyl nuclear power plant was hit by a cyberattack Tuesday and monitoring was being carried out manually, according to a Ukrainian federal agency.
Severe thunderstorm watch in effect until 8 pm
The strength of the storms that form Monday afternoon and the timing of how quickly they pass will depend on the sunshine we see. A severe thunderstorm watch is also in effect until 8 p.m., according to a watch issued by the weather service at 11:15 a.m.