Learn Farsi: دیروز سرور شرکت توسط یک کاربر ناشناس دستبرد خورد. - Yesterday, the company's server was robbed by an unknown user.

In compound verbs, خوردن can also mean "to suffer" or "to be struck by." The active verb for "to rob" or "to raid" is دستبرد زدن (dastbord zadan). By swapping the active light verb زدن (to hit/strike) with خوردن, we create a "lexical passive": دستبرد خوردن (dastbord khordan), which means "to suffer a robbery" or "to be robbed."

We previously learned that Farsi passives usually drop the doer entirely. Why is توسط (tavasot-e) used to say "by an unknown user" here?

While standard grammatical passives with شدن (shodan) usually omit the doer, formal or journalistic Farsi sometimes includes the agent using توسط (by means of / via). Additionally, because دستبرد خوردن is a lexical passive (meaning grammatically it's just a regular verb meaning "to suffer a robbery"), it feels much more natural to include the source of the action than it would with a strict شدن passive.

What are the root words that make up the noun دستبرد (dastbord)?

It is made of دست (dast, hand) and برد (bord, winning/carrying away, from the verb بردن). Literally meaning "hand-taking," it translates to a robbery, raid, or theft. When applied to a server or computer system, as in this sentence, it implies a hack or data breach.