저희가 어떤 조치를 어떻게 취해야 하는지 알려 주시면 감사하겠습니다"--->You are an identity theft victim. The best step is to report it to the police as identity theft. They will likely do nothing, but what you want is the police report.With the police report, even the most hard-nosed IRS person will adjust your account, if the person used your social for tax purposes.Also, you need to contact yur bank to change your bank ; if someone stole money from your bank or credit card accounts, or opened new accounts, the police report also comes in handy. If it was used to open a credit card account, to apply for insurance, to borrow money from a bank, or for similar purposes, this should be reported to the police, Experian, Trans Union, and Equifax, and a "fraud alert" or "credit freeze" should be placed on your file.If it was used for employment, this should be reported to the Social Security Administration. If the person who used it for employment was an illegal alien, then it should also be reported to Immigration and Customs Enforcement. ALSO contact ederal Trade Commission (FTC) to report what happened. You can call the FTC's ID Theft Hotline-1-877-IDTHEFT (438-4338) or use the FTC's online ID Theft Complaint form. for up-to-date information about how to work with credit bureaus and law enforcement agencies to reclaim your identityPlease visit the credit alerts website here for more info; https://www.alerts.equifax.com/AutoFraud_Online/jsp/fraudAlert.jsp