Maybe they got too much attention, and their government or even competitors saw them as an threat?
It's more likely their government stepped in a said
cool it and stop offering superb free anti-malware software/technology for
free to western markets.
I don't see competitors seeing them as a
threat, they are much more likely to
buy/invest in the company and take it over than sabotage it.
When something is too successful at stopping malware usually it's bought out by
bigger fish and their technology is incorporated into another product.
The problem is where they come from and located in. It's not known for transparency and what the government says is really the final word.
*edit*
Forgot to mention it's very close to Lunar New Year (Chinese New Year ) and 99% of people/companies/businesses are closed or on skeleton staff for the holidays in the Asia region. It could be that and it's just their down time, but it doesn't look good! Though who knows!