[nsp] Router running out of memory

[Krzysztof Adamski]

I'm maintaining a network for a customer, it is hub and spoke design,
the spoke links are 802.1q VLANs to the hub, no VPN.
The hub router is a 2621 with 64MB of memory.
The customer has few hundred PCs at different sites, now they are infected
with something that is scanning the world for more machines to infect.

The hub router is running out of processor memory, withing about 10
minutes after reboot it has:
                Head    Total(b)     Used(b)     Free(b)   Lowest(b)  Largest(b)
Processor   81669824    31025116    28080224     2944892       79752       50052
      I/O    3400000    12582912     1981184    10601728    10571664    10573980

If I try to enable CEF I get:
%DCEF not supported with 802.1q encapsulation on subinterface
%CEF not supported with 802.1q encapsulation on subinterface

Is there anything that can be done to prevent this? Would a bigger router
be better?

K