Caller ID services can be susceptible to fraud. "Caller ID spoofing" is a practice that can deliberately falsify a telephone number and name to disguise the identity of the calling party. In this situation, it appears the caller tricked the caller ID system into falsely displaying the USCIS E-Verify support number.
USCIS is aware of a number of calls made to individuals in which the caller fraudulently posed as an immigration official, E-Verify representative, or other government official.