* Oil prices hit a more than three-week high
* Cisco provides biggest boost to Nasdaq
* Indexes up: Dow 0.37 pct, S&P 0.39 pct, Nasdaq 0.37 pct (Updates to late afternoon, adds commentary, changes bylines)
By Sinead Carew
May 15 (Reuters) - Wall Street indexes were trading higher on Monday and the S&P 500 and Nasdaq hit records as a global cyber attack boosted technology stocks and a rise in oil prices lifted energy stocks.
Oil hit its highest in more than three weeks after top exporters Saudi Arabia and Russia said supply cuts needed to last into 2018, a step towards extending an OPEC-led deal to support prices for longer than originally agreed.
"Stronger energy prices today is certainly affecting the energy sector. Otherwise, earnings continue to be good and that's giving investors confidence," said Bryant Evans, investment advisor and portfolio manager at Cozad Asset Management, in Champaign, Illinois.
About 75 percent of S&P 500 companies that have reported results so far have beaten Wall Street expectations according to Thomson Reuters data.
At 2:46 PM ET, the Dow Jones Industrial Average was up 77.88 points, or 0.37 percent, to 20,974.49, the S&P 500 had gained 9.44 points, or 0.39 percent, to 2,400.34 and the Nasdaq Composite had added 22.90 points, or 0.37 percent, to 6,144.13.
Johnson & Johnson and Cisco Systems were the biggest boosts for the S&P 500 after those stocks were upgraded by prominent analysts.
Shares of cyber security firms jumped with Fireye rising 8 percent and Symantec and Palo Alto Networks both gaining 3 percent. The 2.7 percent rise in Cisco shares was also at least partly thanks to its security technology business.
Nine of the 11 major S&P 500 sectors were higher, with the materials index leading the percentage gainers.
Shares of oil majors Exxon and Chevron helped boost the S&P energy index, which was on track to close higher after two sessions of declines.
Some investors however were surprised by the lack of market concern about a successful missile test by North Korea and a cyber attack that disrupted operations at car factories, hospitals, shops and schools.
Also the New York Federal Reserve said on Monday its barometer on business activity in New York state unexpectedly fell in May, putting it into negative territory for the first time since October.
"(The market) hasn't been impacted by the cyber attack, no one is getting nervous about North Korea, no one is getting nervous about the lack of reforms in D.C., no one is getting nervous about the horrendous Empire State number this morning. It seems to be completely disconnected from everything," said Ken Polcari, director of the NYSE floor division at O’Neil Securities in New York.
Advancing issues outnumbered declining ones on the NYSE by a 2.95-to-1 ratio; on Nasdaq, a 1.95-to-1 ratio favored advancers.
The S&P 500 posted 44 new 52-week highs and 10 new lows; the Nasdaq Composite recorded 133 new highs and 48 new lows. (Additional reporting by Caroline Valetkevitch in New York, Tanya Agrawal in Bengaluru,; Editing by Sriraj Kalluvila and Alistair Bell)