Bank A should file a suspicious transaction report (STR) on the transaction in Country A, as it is the financial institution that observes and processes the suspicious activity in its jurisdiction. According to the FATF Recommendations, financial institutions should report any transaction that they have reason to suspect is related to money laundering, terrorist financing, or other criminal activities, regardless of the amount involved1. The STR should include information about the originator, the beneficiary, and the purpose of the transaction, as well as the reasons for suspicion2. Bank A should also comply with any legal or regulatory requirements in Country A regarding the reporting of cross-border wire transfers3.
1: FATF Recommendation 20 - Reporting of suspicious transactions
2: FATF Interpretive Note to Recommendation 20
3: FATF Recommendation 16 - Wire transfers
Reference:http://www.fatf-gafi.org/media/fatf/documents/recommendations/pdfs/FATF%
20Recommendations%20(approved%20February%202012)%20reprint%20May%202012%20web%20version.
pdf(page
19, DNFBPs: customer due diligence, bulleted point (b))

According to the Bank Secrecy Act (BSA), a financial institution or business must establish an anti-money laundering (AML) program that includes at least four elements: (a) a system of internal policies, procedures and controls to prevent, detect and report money laundering and other illicit activities; (b) a designated compliance officer who is responsible for overseeing the implementation and effectiveness of the AML program; an ongoing employee training program that covers the legal and regulatory obligations, the risks and red flags of money laundering, and the roles and responsibilities of the staff in the AML program; and (d) an independent audit function that tests and evaluates the adequacy and compliance of the AML program12.
While the Office of Foreign Assets Control (OFAC) is a key agency that enforces economic and trade sanctions against targeted foreign countries, entities and individuals, it is not part of the BSA or the AML program requirements. However, financial institutions and businesses are expected to comply with OFAC regulations and screen their customers and transactions against the OFAC lists of sanctioned parties. Failure to do so may result in civil or criminal penalties34. Therefore, it is advisable for financial institutions and businesses to have an OFAC program that is integrated with their AML program, but it is not a mandatory element that they have to specifically address in their AML program.
1: Financial Crimes Enforcement Network (2020). Anti-Money Laundering Programs
2: ACAMS (2020). CAMS Certification Package (6th Edition)
3: Office of Foreign Assets Control (2023). Sanctions Programs and Country Information
4: Moses & Singer LLP (2023). Anti-Money Laundering, Bank Secrecy and OFAC Regulations

Lawyers who lack experience in providing specific services requested by clients or receive unusually high fees can raise red flags for money laundering. Inadequate documentation of case notes may also be suspicious, but the absence of experience and excessive fees are more significant indicators. These behaviors warrant further scrutiny to assess potential money laundering risks12.
References:
1. ComplyAdvantage: AML Red Flags - What are the Top 10 Indicators?
2. HyperVerge: AML Red Flags: A Guide to Identification and Response

A key reason why a FI conducts an enterprise-wide AML risk assessment is to assess money laundering and terrorist financing risks and ensure there are adequate controls to mitigate those risks. An enterprise-wide AML risk assessment allows the FI to identify and appropriately manage the ML/TF and other illicit financial activity risks within its banking operations. It also helps the FI to establish global AML control standards and determine the effectiveness of its AML risk management program, including internal preventive and detective controls. By understanding its risk profile, the FI can better apply appropriate risk management processes to the BSA/AML compliance program to mitigate and manage risk and comply with BSA regulatory requirements. The BSA/AML risk assessment should provide a comprehensive analysis of the FI's ML/TF and other illicit financial activity risks, and should be documented in writing and communicated to all relevant stakeholders.
1: Enterprise Wide AML, CTF,Sanctions Risk Assessment (EWRA ... - Eloquens2
3: BSA/AML Risk Assessment - FFIEC BSA/AML3
2: ACAMS Study Guide for the CAMS Certification Examination2

The most appropriate step for an AML compliance officer to take upon receiving notice of government update including the names of the latest terrorists sanctioned by the United Nations Security Council is to update the monitoring software containing sanctioned persons. This is because the AML compliance officer is responsible for ensuring that the financial institution does not engage in any transactions or business relationships with individuals or entities that are subject to sanctions, as this could expose the institution to legal, regulatory, and reputational risks. By updating the monitoring software, the AML compliance officer can ensure that the institution's screening and filtering systems are up to date and can flag any potential matches or hits with the sanctioned persons. This would also enable the AML compliance officer to take appropriate actions, such as blocking or freezing funds, reporting to the relevant authorities, and conducting further due diligence, if necessary.
Anti-Money Laundering (AML) | FINRA.org, Overview.
AML Compliance Officer and Their Responsibilities - Tookitaki, Role and Responsibilities of an AML Compliance Officer.
What is an AML Compliance Officer? - Sanction Scanner, Communicate openly with the company's internal management team.
Guidance on Existing AML Program Rule Compliance ... - FinCEN.gov, Financial Institutions Toll-Free Hotline.