Flaws threaten Microsoft SEATTLE — Microsoft Corp.'s offer this week of cash bounties for informants who help it collar virus-writers reflects more than just an escalation of the war on those who would exploit the dominant power in software. The campaign reveals just how much of a threat to Microsoft's bottom line security flaws now represent. When the Blaster worm hobbled hundreds of thousands of computers around the world in August — only the latest plague to exploit a flaw in Windows operating systems — it also hurt Microsoft's ability to book new contracts with corporate customers. For the first...