Following the arrival of an ancient Egyptian artifact, museum employees begin to get murdered one by one. Now, a security guard who is dissatisfied with her job must solve the murders and catch the killer before she becomes the next victim.

I really like SyndneyPaul and TorDollhouse's comments.

"After a grizzly string of murders, a fed up museum security guard blames a recent Egyptian exhibit and must solve the ancient curse before the next full moon."

Include a "ticking clock" to give us more urgency. This helps put pressure on the protagonist and fuel the fire. Hope this helps :D

Interesting premise, paints a good picture. However you could tighten up the logline, and I'd also suggest leaving it more open as to who or what is responsible for the killing, given the mystery of the artifact (ie, is it someone who wants the artifact, or is the artifact itself somehow responsible??).

Here is a tighter version that may provide some ideas:

"When a museum acquires a mysterious Egyptian artifact and staff begin turning up dead, a disgruntled security guard must unravel the source of killings before she becomes the next victim."

Hope that's useful, cheers