No, they had too few for large-scale attack.
Though it’s possible that some individual Death Eaters may still have attacked the “good” side, after the war, there weren’t many Death Eaters left for them to make any sort of large-scale resurgence after the war. The number of Death Eaters who were available and willing to attack without the Dark Lord’s protection was severely diminished from the number of Death Eaters who were active during the height of the war. Many had been killed in the war, others were fleeing to avoid imprisonment, and some were being captured.
“He must speak to the bereaved, clasp their hands, witness their tears, receive their thanks, hear the news now creeping in from every quarter, as the morning drew on, that the Imperiused up and down the country had come back to themselves, that Death Eaters were fleeing or else being captured, that the innocent of Azkaban were being released at that very moment, and that Kingsley Shacklebolt had been named temporary Minister for Magic …”
- Harry Potter and the Deathly Hallows, Chapter 36 (The Flaw in the Plan)
The Death Eaters didn’t attack again as a group after the Dark Lord’s fall because they wouldn’t have had the chance or the ability to. The Death Eaters who were fleeing wouldn’t have wanted to attack again because they’d almost certainly get caught, and any who wanted to deny their involvement also wouldn’t want to risk attacking. The ones who were being captured may have attempted attacking before their capture, but were caught soon after, so while they may have tried, they wouldn’t have been particularly successful. Then, once they were caught, they’d be sentenced and imprisoned, so they’d no longer be able to attack unless they escaped from Azkaban.
But individual or a few Death Eaters may have.
Although the number of willing Death Eaters was severely diminished making a large-scale attack impossible, there’s no evidence that individual Death Eaters, or groups of a determined few, never attacked anyone on the other side after the war. Though we know nineteen years after the war, at the time of the epilogue, “all was well”, that doesn’t eliminate the possibility of there being a few Death Eaters that attacked people before then. For example, after the first war was over and the Dark Lord fell from power, Bellatrix and a few other Death Eaters attacked the Longbottoms.
“The Longbottoms were very popular,’ said Dumbledore. ‘The attacks on them came after Voldemort’s fall from power, just when everyone thought they were safe. Those attacks caused a wave of fury such as I have never known. The Ministry was under great pressure to catch those who had done it. Unfortunately, the Longbottoms’ evidence was – given their condition – none too reliable.”
- Harry Potter and the Goblet of Fire, Chapter 30 (The Pensieve)
Though they were in theory attempting to get information on where the Dark Lord could be, they also wanted to torture Aurors, which would still be a possible motivation for Death Eaters even after the Dark Lord was known for sure to be dead.
SU: Oh, that's so cool. Can we just ask kind of a sad thing, though. What did the Longbottoms do that they earned that wrath from Bellatrix? Such-- There's three times, like the Potters thrice defied the Dark Lord.
JKR: They were efficient! They were efficient. That's all they needed to do to earn her wrath. They were-- They had rounded up Death Eaters, they were very good Aurors, they knew what they were doing, they were responsible for a lot of captures and arrests and imprisonments. And-- So there you are.
[- PotterCast Interviews J.K. Rowling, part 1 (December 17, 2007)][1]
There also may have been some individual Death Eaters who attempted to attack, since some of them enjoyed torturing and may not have been willing to simply flee.
“There was Antonin Dolohov,’ he said. ‘I – I saw him torture countless Muggles and – and non-supporters of the Dark Lord.”
- Harry Potter and the Goblet of Fire, Chapter 30 (The Pensieve)
Therefore, despite the low numbers of Death Eaters making it impossible for them to truly have a resurgence and the knowledge that nineteen years later all was well, it’s still possible that there were some Death Eaters who attacked after the war.