OPT security check

[mrahmanme]

I have applied for EAD under OPT (initial 12 month) for the first time. Usually it takes less or approximately 90 days. I am on my 142th day today and still didn't get any update whether it is accepted or denied. 

On 78th day I made a service request after calling the customer care, they assigned a reference number and finally I got a reply on 91th day that says, "We have placed your case on a processing hold because the required security checks remain pending. Until we receive the results of these security checks, we cannot move forward on your case. We require the results of security checks before we make a decision on any pending case." 

Later on I made another request after 121th day and got another response on 122th day. It says, "We have received your service request and researched the status of your case. We have had to perform additional review and this has caused a delay in processing time. Your case is currently with an adjudicating officer. You should receive a decision or notice of further action within 60 days." 

Tracked my case number using the USCIS case number and it's still showing "Case was received" 

Can anyone please guide me to overcome the situation and get the EAD?