You are not 'just a translator'. You intentionally changed the URL to point towards a malicious executable.
This has nothing to do with a 'mistake' or with 'being tired'. Uploading malware and changing the links in an ANN thread does not happen on accident.,
Your client could probably even give you a red flag (violating a contract) for this. There are a lot of wannabe-lawyer here who would eat you alive once the flag is created.
Let's be logical. can a full member do this mistake? just look at all fake ann create by the same attacker with the same virus.
you can visit all fake ann to see that https://bitcointalk.org/index.php?action=trust;u=805820