If it is true or not we can never know...bot one thing is for sure:That it is totally possible!
For those of you who don't know downadup or conficker(two alternate names coined by different av and security companies for the same botnet) exploits the ms08-067 vulnerability.
Original f-secure announcements:
https://www.f-secure.com/weblog/archives/00001584.html
https://www.f-secure.com/weblog/archives/00001579.html
https://www.f-secure.com/weblog/archives/00001574.html
Others:
https://www.microsoft.com/security/portal/Entry.aspx?Name=Worm%3aWin32%2fConficker.A
https://www.f-secure.com/v-descs/worm_w32_downadup_al.shtml#details
https://www.symantec.com/security_response/writeup.jsp?docid=2008-112203-2408-99&tabid=1