Hacker Attack?

[glenng3]

Today our switchboard operator was unable to transfer calls to an ACD queue for several minutes. Looking at the CDR records, I see many calls hitting the queue from different numbers at the same time. None of the calls registered any duration, and many of the calling numbers are repeated several times a minute. Could this be a hacking attack? Sample CDR below (numbers truncated in case they are innocent). We have a G3si, CM 3.1.5. Thanks. -G.

Date Time Calling # ACD# ACD# Duration Trunk Member
050213 1454 619578387 5000 5000 0000 811 001
050213 1454 732306634 5000 5000 0000 811 002
050213 1454 816404390 5000 5000 0000 811 001
050213 1454 604806930 5000 5000 0000 811 001
050213 1454 201214253 5000 5000 0000 811 003
050213 1455 201214253 5000 5000 0000 811 004
050213 1455 604806930 5000 5000 0000 811 001
050213 1455 214533012 5000 5000 0000 811 004
050213 1455 732306634 5000 5000 0000 811 005
050213 1455 604806930 5000 5000 0000 811 001
050213 1455 201214253 5000 5000 0000 811 002
050213 1455 201214253 5000 5000 0000 811 001
050213 1455 619578387 5000 5000 0000 811 002
050213 1455 407574227 5000 5000 0000 811 001
050213 1456 619578387 5000 5000 0000 811 003
050213 1456 619578387 5000 5000 0000 811 003
050213 1456 732306634 5000 5000 0000 811 003
050213 1456 201214253 5000 5000 0000 811 003
050213 1456 816404390 5051 5051 0003 811 002
050213 1456 619578387 5000 5000 0000 811 002
050213 1456 305905099 5000 5000 0000 811 003
050213 1456 619578387 5000 5000 0000 811 002
050213 1456 619578387 5000 5000 0000 811 002
050213 1456 619578387 5000 5000 0000 811 002
050213 1456 305740130 5000 5000 0000 811 004

 

[glenng3]

Never mind, we've narrowed this down to a problem with the way staff are leaving a temporary "out of office" voice message. I would erase the original post, but there doesn't seem to be a way to do that. -G.