The sanctioned targets are banned from the US financial system and American citizens and business are prohibited from any transactions with them.
The US Treasury Department's statement defines the new additions to the list of "specially designated nationals" only as "cyber-related" and "Russia-related" designations.The list of entities targeted by the fresh round of US sanctions actually includes a number of cyber-security firms based in Russia, Israel, Europe, and even the US itself.
The sanctions also cover Kvant Scientific Research Institute, which the FSB controls, and Divetechnoservices, which has supplied FSB with "a variety of underwater equipment and diving systems for Russian government agencies" including a $1.5-million submersible craft, according to the Trump administration.
According to Mnuchin, placed under the sanction of the company, "contributed to the improvement of the cyber and undersea capabilities of Russian Federation through their work with FSB".
A computer technician connects a computer into a network server in an office building in Washington, D.C., on May 13, 2017. In detailing the fresh sanctions, the announcement specifically pointed to attacks on the United States power grid and the 2017 NotPetya that targeted Ukraine and other parts of the world as examples of Russian cyberattacks. Aleksandr Lvovich Tribun, Oleg Sergeyevich Chirikov and Vladimir Yakovlevich Kaganskiy - all executives for Divetechnoservices - are the three individuals sanctioned.
No mention of Russian attacks on USA elections was mentioned in the press release.
"The United States is committed to aggressively targeting any entity or individual working at the direction of the FSB whose work threatens the United States and will continue to utilise our sanctions authorities to counter the constantly evolving threats emanating from Russia", Mr Mnuchin said.
The US Treasury department has formally accused Digital Security of "providing material and technological support to the FSB" - the Russian intelligence service.
"Today's action also targets the Russian government's underwater capabilities", said the Treasury, adding: "Russia has been active in tracking undersea communication cables, which carry the bulk of the world's telecommunications data".
"I woke up and was embraced by such news", he said.
Their assets were frozen, and USA citizens were banned any cooperation with sanctioned companies and people.
Updated 6/11/18 15:35 EST: Updated article with statement from ERPScan CTO & Founder Alexander Polyakov.