Approximately 6 months ago an exploit to subtle vulnerabilities found in all Mac OS and iOS was found and reported by security researchers. This is only recently made public because Apple asked the researches to give them 6 months before disclosing the vulnerabilities. Read more about it at Arstechnica.
Serious OS X and iOS flaws let hackers steal keychain, 1Password contents | Ars Technica
For users like me who has all important information stored in apps like 1password, it is advised to install only trusted apps for now just to be safe.