Company Update

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C.  20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 24, 2023 1st Source Corp oration (Exact name of registrant as specified in its charter) Indiana 0-6233 35-1068133 (State or other jurisdiction of incorporation) (Commission File No.) (I.R.S. Employer Identification No.) 100 North Michigan Street , South Bend , Indiana 46601 (Address of principal executive offices)     (Zip Code) 574 - 235-2000 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock - without par value SRCE The NASDAQ Stock Market LLC Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o ITEM 8.01      Other Events. Per its Form 8-K filed July 10, 2023, 1st Source Corporation (the “Company”) disclosed that, as part of the cybersecurity event concerning a software application known as MOVEit impacting numerous organizations and governmental agencies around the world, an unauthorized third-party gained access to sensitive data of commercial and individual clients, including personally identifiable information of individuals. The Company summarized the steps it had taken to eliminate the software vulnerability and steps it was taking to notify and offer clients impacted complimentary monitoring, identity restoration, and fraud detection services. The Company has since notified states attorney generals or other designated state officials as required under state data security notification laws of the incident, including the total estimated number of records impacted of 450,000 which includes the number of impacted residents in all applicable states. Note Regarding Forward-Looking Statements This periodic report on Form 8-K contains statements that are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The Company identifies some of these forward-looking statements with words like “believe,” “may,” “could,” “would,” “will,” “might,” “should,” “expect,” “intend,” “plan,” “target,” “anticipate” and “continue,” the negative of these words, other terms of similar meaning or the use of future dates. Forward-looking statements in this report include, but are not limited to, statements regarding the actual or potential impact of the MOVEit vulnerability, and financial guidance related thereto. There are a number of factors that could cause actual results or future events to differ materially from those anticipated by the forward-looking statements. For further information regarding risks and uncertainties associated with the Company’s business, please refer to the Company’s filings with the Securities and Exchange Commission (the “SEC”), including its Annual Report on Form 10-K for the fiscal year ended December 31, 2022, which was filed with the SEC on February 16, 2023. The Company undertakes no obligation to update any forward-looking statements, which speak only as of the date of this current report on Form 8-K. SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. 1st SOURCE CORPORATION (Registrant) Date: July 24, 2023 /s/ BRETT A. BAUER Brett A. Bauer Treasurer and Chief Financial Officer Principal Accounting Officer