A hacker going by the name Guccifer 2.0 claimed to have published files hacked from the Clinton Foundation on Tuesday, including spreadsheets that appear to show corporate money being funneled to politicians and a computer file titled “pay for play.”

The files—which weren’t posted in their entirety—look conspicuously corrupt, and their presentation seems designed to confirm long-standing suspicions that the foundation is indeed a pay for play operation that trades off the the Clinton family’s past, present, and potential future influence.

But there’s a problem. The president of the Clinton Foundation says the documents aren’t theirs, and there’s no evidence that the organization’s networks have been breached. So, is this the October surprise that Clinton’s opponents have been expecting? Or is it the next stage in what intelligence officials suspect is an ongoing “active measures” campaign to meddle with the U.S. election?

Disinformation is a classic technique used by intelligence agencies to sow doubt and confusion among their adversaries. Ever since the theft of emails from the Democratic National Committee in July, intelligence officials, while declining publicly to identify Russia as the culprit, have braced for the moment when hackers would start to litter the Internet with fake documents and emails that couldn’t be easily refuted and would seized by some as facts.

Russia has already perfected the art of disinformation in the Internet age, and on an industrial scale. The country is suspected of having engineered a flood of fake or misleading claims that Sweden was about to stockpile nuclear weapons that could be used against Russia. Russian media outlets spread a similarly bogus claim about nukes in a Turkish base being at risk. And let’s not got into Moscow’s laughable assertions about the lack of Russian troops in Ukraine—or the identities of those who shot the MH17 passenger plane of the sky. Journalist Adrian Chen, who uncovered an “army of well-paid trolls” working for the Kremlin, said they were at one point also likely being paid to spread propaganda to bolster Donald Trump.

It’s possible that the Clinton Foundation doesn’t realize it was really hacked. Bloomberg reported in June that the foundation had, in fact, been breached. The foundation said it hadn’t been notified of any intrusions and declined to comment further.

But Tuesday’s denial, from foundation president Donna Shalala, went a step further, insisting that the purportedly purloined documents weren’t actually from the foundation at all.

And the hacker in question, Guccifer 2.0, has his own troublesome pedigree. Security experts say that whomever is behind the online facade is likely an agent working for Russia. Guccifer 2.0 is also suspected of being the source of the hacked DNC emails to WikiLeaks, which published them and promised more damning information about Clinton.

Clinton’s opponents, and Trump’s supporters, eagerly expected WikiLeaks’ founder Julian Assange to make good on his tease of a bombshell to influence the election. But in his press conference Tuesday morning, he offered no new emails and instead spent his time trumpeting WikiLeaks’ past successes.

So, is Guccifer 2.0’s own email dump the real October surprise the anti-Clinton camp had hoped for? If so, he may have to work harder to prove it.