Lucknow, June 25 -- A city-based businessman lost Rs.18 lakh in a sophisticated cyber fraud after his accountant received a malware-infected WhatsApp message from fraudsters impersonating the businessman's son, police said on Wednesday. The case came to light after the victim approached the Cyber Crime Police Station in Lucknow, alleging that cyber criminals had gained access through a malicious file sent via WhatsApp and subsequently siphoned off Rs.18 lakh from business-related accounts. "Acting on the complaint, the cyber crime unit launched an investigation and coordinated with multiple banks and financial institutions to trace the money trail. Police said their efforts led to the recovery of Rs.6 lakh, which has been returned to the complainant, while another Rs.5.5 lakh has been frozen in various bank accounts," said Adcp crime Kiran Yadav. Officials said the fraudsters had used a common social-engineering tactic by posing as a trusted family member to lower suspicion and persuade the accountant to open the malware-laced message. Once the file was accessed, the attackers allegedly gained unauthorised access to financial information and executed fraudulent transactions. "The cyber crime police took swift action and successfully facilitated the return of Rs.6 lakh to the victim while freezing another Rs.5.5 lakh. Efforts are underway to recover the remaining amount and identify the accused involved in the fraud," said Yadav. Police said the investigation is continuing to trace the beneficiaries of the transactions and ascertain whether the fraud is linked to a larger cybercrime network operating across states. Expressing gratitude to the cyber police, the complainant said the prompt intervention had strengthened his hope of recovering the remaining amount. The cyber crime unit has advised citizens not to download files, APKs or applications received through unsolicited messages and to refrain from sharing banking credentials, UPI details or OTPs with anyone. In case of suspected cyber fraud, victims have been urged to immediately report the matter on the national cybercrime helpline 1930 or through the cybercrime reporting portal....