It's certainly possible that the infosec apparatus of the USG government, at its highest levels, could forge a compromise of the DNC. They have the requisite intelligence to leave the right trial of breadcrumbs to trick firms like Crowdstrike.

But I don't think it's very plausible. Break this down a bit:

* Possibility 1: The NSA/CIA/DHS deliberately attack the Democratic National Committee --- a black-letter crime --- and deliberately create a fraudulent attribution to Russia. In the process, they reveal unflattering secrets about the party of the government still in power, and generate fodder for one of the most volatile Presidential elections in recent history. Plausibility rating: HIGHLY IMPROBABLE.

* Possibility 2: The attack isn't instigated by the US government, but rather some group of randos who the USG finds convenient to frame for the attack. Since the attribution work is performed simultaneously by US federal law enforcement and multiple attribution firms, a conspiracy must be generated between the firms (who are unanimous in their opinion) and law enforcement --- and, since the act of framing Russia is both deliberate and highly strategic, probably the executive branch of the US government at the highest levels. This is technically possible to accomplish, but would represent the most sophisticated and ambitious conspiracy undertaken by the US government in the last 50 years. Plausibility rating: EVEN LESS PROBABLE.

* Possibility 3: Both the USG and the attribution firms believe in good faith that they have a firm attribution to Russia. But they're wrong. For example, perhaps Russia seeded the last generation of their attack tools to a bunch of randos in Eastern Europe. Problem: tools, implants, and exploits are important IOCs, but they aren't the only ones, and the attribution depends on some IOCs that can't be seeded --- previously used staging servers and command and control systems. Plausibility rating: SLIGHTLY MORE PLAUSIBLE BUT STILL IMPROBABLE.

* Possibility 4: As bystanders we don't have a clear enough understanding of Russia's M.O. to gauge their intent. We agree broadly that Russia is highly competent and capable, and that this is a high-profile attack, so it's unlikely that they were just too dumb to set up fresh staging servers. So Russia is comfortable with the world knowing they're doing this; in addition to hamfistedly manipulating the election and supporting their favorite candidate --- we know Trump is their favorite candidate, they just filed a complaint to the U.N. to that effect!!! --- they're also communicating something to the US about their willingness to sow chaos and exploit it to their own ends. Plausibility rating: SUBJECTIVE.