<p><img src="https://static3.businessinsider.com/image/5bc9e6fd7e42392a9a18aae3-2400/2018-10-19t135950z1834682224rc18709324e0rtrmadp3solarwind-ipo.jpg" border="0" alt="SolarWinds" data-mce-source="Reuters/Brendan McDermid" data-mce-caption="SolarWinds Corp. banner hangs at the New York Stock Exchange (NYSE) on the IPO day of the company in New York."></p><p></p><bi-shortcode id="summary-shortcode" data-type="summary-shortcode" class="mceNonEditable" contenteditable="false">Summary List Placement</bi-shortcode><p>The US Senate is questioning SolarWinds and other tech firms in a hearing Tuesday after unknown attackers, <a href="https://www.wsj.com/articles/suspected-russian-hack-extends-far-beyond-solarwinds-software-investigators-say-11611921601">with suspected links to Russia</a>, infiltrated the company's software last year, compromising thousands of organizations including major federal agencies.</p><p>SolarWinds is joined in the hearing by FireEye, a cybersecurity firm that <a href="https://www.businessinsider.com/fireeye-mandiant-solarwinds-microsoft-hackers-not-done-gathering-data-2021-1">first discovered the malware in December</a>, as well as Microsoft, whose president, Brad Smith, will be present in the proceedings. CrowdStrike CEO George Kurtz will also testify; his cybersecurity firm was apparently able to stave off the hackers.</p><p>The cyberattack began in March of last year and went undetected for months. SolarWinds told the SEC that about 18,000 of its 300,000 clients were targeted in the attack. High-level government data was left exposedthe <a href="https://www.nytimes.com/2020/12/13/us/politics/russian-hackers-us-government-treasury-commerce.html'action=click&module=Top%20Stories&pgtype=Homepage">Trump administration confirmed in December</a> that hackers had indeed infiltrated key networks, including the US Treasury and the Commerce Department.</p><p><em><strong>Read more:</strong><a href="https://www.businessinsider.com/solarwinds-supply-chain-hack-fireeye-russia-cybersecurity-payton-2020-12'r=kc-sub" data-analytics-module="body_link" data-analytics-post-depth="80" data-uri="c2cc1946fbcba59c3699c12cdf135e70">Why the impact of the unprecedented SolarWinds hack that hit federal agencies is 'gargantuan' and could hurt thousands of companies, according to cybersecurity experts</a></em></p><p>Fortune 500 companiesincluding Microsoft, AT&T, and McDonald'swere among SolarWinds' vulnerable customer base. Microsoft has said its products, including its Office 365 suite and Azure cloud, were not used in the hack, but they were targeted. And <a href="https://www.businessinsider.com/fireeye-mandiant-solarwinds-microsoft-hackers-not-done-gathering-data-2021-1">FireEye researchers say the hackers appear to be able</a> to send emails and access calendars on Microsoft's 365 suite.</p><p><em><strong>Read more:</strong> <a href="https://www.businessinsider.com/microsoft-solarwinds-cyberattacks-transparency-fireeye-cybersecurity-hackers-2021-2'r=kc-sub">Microsoft said its software and tools were not used 'in any way' in the SolarWinds attacks. New findings suggest a more complicated role</a></em></p><p><a href="https://www.businessinsider.com/biden-official-solarwinds-attack-response-may-come-within-weeks-2021-2">The White House has said it may respond</a> to the SolarWinds hacks in a matter of weeks.</p><p>As Insider reported, <a href="https://www.businessinsider.com/senate-solarwinds-hearings-fireeye-microsoft-crowdstrike-cybersecurity-2021-2">Tuesday's hearing will be a pivotal moment in the relationship</a> between the US government and the cybersecurity world, namely how the industry can help federal officials stave off nation-state attacks in the future.</p><p>You can watch the live stream below. Follow along here for live updates from the hearing.</p><div><iframe width="560" height="315" src="//www.youtube.com/embed/IPozXgMqMag" frameborder="0" allowfullscreen></iframe></div><p></p><p><strong>SEE ALSO: <a href="https://www.businessinsider.com/fireeye-mandiant-solarwinds-microsoft-hackers-not-done-gathering-data-2021-1" >SolarWinds hackers are expanding espionage data-gathering and gaining powerful access to Microsoft cloud apps, FireEye researchers say</a></strong></p><p><a href="https://www.businessinsider.com/watch-live-senate-hearing-solarwinds-microsoft-fireeye-crowdstrike-cyberattack-2021-2#comments">Join the conversation about this story »</a></p> <p>NOW WATCH: <a href="https://www.businessinsider.com/electric-planes-future-of-aviation-problems-regulations-2020-3">Why electric planes haven't taken off yet</a></p> Click here to read full news..