The distributed denial of service (DDoS) attack was aimed at the website of industry expert Brian Krebs.
At its peak, the attack aimed 620 gigabits of data a second at the site.
Text found in attack data packets suggested it was mounted to protest against Mr Krebs' work to uncover who was behind a prolific DDoS attack.
In a blogpost, Mr Krebs detailed the attack, which began late on Tuesday night and quickly ramped up to its peak attack rate.
DDoS attacks are typically carried out to knock a site offline - but Mr Krebs' site stayed online thanks to work by security engineers, who said the amount of data used was nearly twice the size of the largest attack they had ever seen.
"It was among the biggest assaults the internet has ever witnessed," added Mr Krebs.
Security firm Akamai said the attack generated such a huge volume of data by exploiting weak or default passwords in widely used net-connected cameras, routers and digital video recorders. Once in control of these "smart" devices the attackers used them to swamp the site with data requests.
"These new internet-accessible devices can bring great benefits, but they are also an increasingly easy and lucrative targets for cybercriminals," said Nick Shaw from security firm Symantec.
The security firm has carried out research which shows swift growth in the number of malware families scouring the net for vulnerable devices. Typically, said Mr Shaw, malicious hackers who take over gadgets are not interested in stealing personal data.
"Cybercriminals are interested in cheap bandwidth to enable bigger attacks," he said.
Mr Krebs speculated that the attack could have been prompted by an article he published, in early September, that named two young men allegedly associated with a service called vDos that carried out DDoS attacks for cash.
Soon after the article was published, Israeli police arrested the two men named by Mr Krebs. Released on bail, the pair were barred from using the net for 30 days.
Buried inside many of the data packets despatched towards Mr Krebs' site was text calling for the release of one of the men named in that article.
"I can't say for sure, but it seems likely (to be) related," said Mr Krebs.

Four years ago, Professor Anthony King criticised the BBC at a UK level for ignoring political developments in Wales and Scotland.
But in a Royal Television Society Wales lecture he said there had been "an enormous change" in how the BBC now reported on devolved nations.
However, he said more could be done to compare policies across the UK.
Delivering his speech at the RTS Wales annual lecture, Prof King said he believed that while mistakes still happen - it was much less common.
"I think there has been enormous change," he said.
"I live in the east of England, I look out for the failure of the BBC to mention what is going on in Wales, what's going on in Scotland and to give the impression that everything that affects England affects everybody else in the UK.
"They make many fewer mistakes than they used to."
His comments are in stark contrast to a review he carried out for the BBC Trust in 2008.
In that report, the professor of government at Essex University, stated that the BBC was "not reporting the new UK with the range, clarity and richness that might reasonably be expected".
Speaking in Cardiff on Thursday evening, he said the task now at hand for the BBC was to show more clearly just how devolution impacted on everyday policies across the UK.
"If the NHS is run differently in Wales than the way it is run in England, I want to know why it is run differently, how it is run differently, and what difference that makes to the people of Wales," he said.
"I think it is still the case that the English don't quite take on board the reality of devolution.
"They know about it as a concept, but they don't really know what its meaning is on the ground, and they don't know that things are going on very differently in different parts of the country, with very different outcomes."
One of the biggest web attacks ever seen has been aimed at a security blogger after he exposed hackers who carry out such attacks for cash.
[NEXT_CONCEPT]
The BBC's coverage of Welsh devolution has significantly improved on UK-wide programmes, says a leading academic.