The insidious effects of small billing errors cost our company thousands over the year.

小額帳單錯誤暗中造成的影響，一年下來讓公司損失了數千元。

Our IT team warned staff about an insidious phishing email disguised as a payroll update.

資訊部門警告員工，有一封偽裝成薪資更新通知的陰險釣魚郵件。

Hidden fees in the hotel package proved insidious, doubling the final cost of our trip.

飯店套裝行程裡的隱藏費用暗中作祟，讓我們的旅費最後翻了一倍。