I had been wondering how long it would take spammers to figure this one out. Here is what has been happening for the last week or two.
Spammers have been looking for blogs that do not have any kind of spam protection or are weak and have let some spam links through. They then monitor those blogs for activity to see if they are being used/check often. If they find that the blog is uninhabited, they then start adding links pointing to those spammed posts in their new spam comments to be sent to unsuspecting bloggers. Thus by making the links to blogs in their spam comments look somewhat eligible (and in a foreign language) the spammers are raising the pagerank of those spammed posts in “compromised” blogs and effectively giving their own spam links the attention they need.
I suggest that all bloggers become proactive about spam. Please keep your spam filters updated and actively remove commenting from old posts beyond a certain age (if you are unwilling to weed out comment spam). I suggest an intelligent comment detection mechanism and I believe it already exists for WordPress in some form. If a post is of a certain age and it suddenly receives comments, they deserve to be moderated and then allowed by the blog author.
I see this quickly becoming a major problem since quite a few abandoned blogs exist and some established bloggers still allow comment spam to seep through into their blogs.