Two US lawmakers who are members of their respective intelligence committees said Thursday that a spate of recent cyber attacks suggests Russia is trying to disrupt the November election.

"Based on briefings we have received, we have concluded that the Russian intelligence agencies are making a serious and concerted effort to influence the US election," said a statement from Senator Dianne Feinstein and Representative Adam Schiff, both Democrats from California.

"At the least, this effort is intended to sow doubt about the security of our election and may well be intended to influence the outcomes of the election -- we can see no other rationale for the behavior of the Russians."

US officials have stopped short of blaming Moscow for the wave of computer intrusions, but many analysts have said the attacks appear to be from Russian hackers.

Feinstein and Schiff, who as members of their intelligence committees receive classified briefings, said they believe that the hacks "could come only from very senior levels of the Russian government" and called in Russian President Vladimir Putin "to immediately order a halt to this activity."

"Americans will not stand for any foreign government trying to influence our election," they said.

"We hope all Americans will stand together and reject the Russian effort."

The recent breach of Democratic National Committee data, along with other electronic intrusions, has raised concerns about cyber incidents that could affect the outcome of the US presidential race, or other contests.

The campaign of Democratic presidential candidate Hillary Clinton said one of the hacks had accessed an analytics data program.

Cybersecurity experts see a potential for more hacks and incidents in the coming months which could hurt the integrity of the election campaign.

Yahoo hack is latest major cyber-attack
Paris (AFP) Sept 23, 2016 - The massive hacking attack on Yahoo revealed Thursday is one of biggest thefts of online users' personal information ever, affecting some 500 million accounts.

For Tanguy de Coatpont, head of the French and North African divisions of Kaspersky Lab, a computer security company, it is "the biggest in history involving a single company".

Michael Bittan, a risk manager at Deloitte, cautioned that it was "the biggest to be made public. There have possibly been others that were bigger".

At any rate, it is far from the first, and here are other notable major corporate hacks of recent years:

- Taking aim at Target -

US retail giant Target was hit by a computer attack in December 2013 that affected 110 million clients. Seventy million might have lost personal data including names, addresses, phone numbers and e-mail accounts, while 40 million bank accounts and credit cards were also put at risk.

- South Korea scramble -

- In January 2014, South Koreans scrambled to stop money being siphoned from their bank accounts after it emerged that data on 20 million credit cards had been stolen over several years.

The data was swiped by an employee from the personal credit ratings firm Korea Credit Bureau, who then sold it to telemarketing companies.

- Password plunder -

- In August 2014, online data protection firm Hold Security claimed that Russian hackers had accessed 1.2 billion passwords linked to 420,000 internet sites around the world, from corporate giants to individual accounts. Hold Security pointed to a group of hackers called "CyberVor", which it said had potentially gained access to 500 million e-mail accounts.

- Too hot to handle -

In August 2015, hackers calling themselves The Impact Team published nearly 30 gigabytes of files including the names and credit card data of people who had signed up with Ashley Madison, a website for those who wanted to have extra-marital affairs.

The company's boss stepped down as several suicides were linked to the revelations.

Ashley Madison had earlier offered to delete users personal data for a modest fee, but did not, resulting in the launch of a class-action lawsuit estimated at Can$760 million (US$578 million).

- Apple in crosshairs -

In September 2015, computer security experts discovered a virus dubbed "KeyRaider" that targetted Apple iPhones and iPads, and which had already affected 225,000 Apple accounts.

The virus intercepted communications with Apple's iTunes music store, stealing information as purchases were made. Users in 18 countries were affected.