Etilin, a managing director at AlixPartners consulting firm, was named interim CFO in September. She had previously held the role from July 2013 until February 2014.
Just last week, the electronics chain posted a net loss of $161.1 million for the third quarter, on top of yet another drop in overall and comparable-store sales. In an SEC filing that day, the company reiterated its warning that it may be required to seek bankruptcy protection.
Read MoreRadioShack lives another day
Then, on Friday, a committee of the International Swaps and Derivatives Association determined that no credit event had taken place when RadioShack entered into a refinancing agreement with Standard General in October.
Salus Capital, one of RadioShack's key lenders, had argued the agreement breached the terms of its loan, and demanded immediate payment.
As part of CEO Joe Magnacca's plan to save $400 million annually, RadioShack is seeking lender approval to close 1,100 stores. Earlier this year, that plan was blocked by Salus.
As of Nov. 1, RadioShack's total debt was $841.5 million, and it had total liquidity of $62.6 million.
Its shares fell 11 percent to about 35 cents in early trading.