China's iaskspider evolution and related crawling

Here's the latest on this little bullshit bot iaskspider from China.

Previously it crawled from 2 d-blocks using a simple name:

219.142.118.56 "iaskspider"
219.142.118.57 "iaskspider"
219.142.78.60 "iaskspider"
219.142.78.85 "iaskspider"

Now it claims to be Internet Explorer:

219.142.118.66 - "Mozilla/5.0 (compatible; iaskspider/1.0; MSIE 6.0)"

And appears to be checking anonymously for spider traps or some shit:

219.142.118.75 - "GET /robots.txt HTTP/1.0" 200 146 "-" "-"
219.142.118.70 - "GET /robots.txt HTTP/1.0" 200 146 "-" "-"
219.142.118.69 - "GET /robots.txt HTTP/1.0" 200 146 "-" "-"
219.142.118.54 - "GET /robots.txt HTTP/1.0" 200 146 "-" "-"

Don't ask me, I only block them, no clue what the hell is going on.