To pilfer or filch — to steal small items stealthily (colloquial, often implies petty theft).
子どもがクッキーをくすねて食べてしまった。
The child pilfered a cookie and ate it.
社員が備品をくすねていたことが発覚した。
It was discovered that an employee had been filching office supplies.
市場で財布をくすねられたと警察に届けた。
I reported to the police that my wallet had been pilfered at the market.