From the Button down the hatches dept.:
The number of brute-force SSH attacks is rising, the SANS Internet Storm Center warned on Monday.

"[T]here has been a significant amount of brute force scanning reported by some of our readers and on other mailing lists," said Internet Storm Center handler Scott Fendley in a blog post. "... From the most recent reports I have seen, the attackers have been using either 'low and slow' style attacks to avoid locking out accounts and/or being detected by IDS/IPS systems. Some attackers seem to be using botnets to do a distributed style attack which also is not likely to exceed thresholds common on the network."

informationweek.com