1. A host system comprising a hardware processor and a memory, the hardware processor configured to execute a target entity, a synchronous exception analyzer, and an asynchronous exception analyzer, wherein the hardware processor is further configured to: in response to detecting an occurrence of an event caused by an execution of the target entity, suspend the execution of the target entity, and in response to suspending execution of the target entity, switch to executing the synchronous exception analyzer; wherein the synchronous exception analyzer is configured to: determine whether the target entity is suspect of being malicious according to the event, in response, when the target entity is suspect of being malicious, selectively retrieve a rule exception signature from a plurality of rule exception signatures, the rule exception signature retrieved according to the event, wherein the rule exception signature comprises an encoding of a first condition and an encoding of a second condition, in response to retrieving the rule exception signature, determine whether the first condition is satisfied according to the event and according to the target entity, in response to determining whether the first condition is satisfied, when the first condition is satisfied, cause the hardware processor to resume execution of the target entity, and in response to determining whether the first condition is satisfied, when the first condition is not satisfied, determine that the target entity is malicious; and wherein the asynchronous exception analyzer is configured to: in response to the hardware processor resuming execution of the target entity, determine whether the second condition is satisfied according to the event and according to the target entity, in response to determining whether the second condition is satisfied, when the second condition is satisfied, determine that the target entity is not malicious, and in response to determining whether the second condition is satisfied, when the second condition is not satisfied, determine that the target entity is malicious.