X0306 4 2022-08-15 0 0001370880 Mandiant, Inc. MNDT 0001595602 Mandia Kevin R. C/O MANDIANT, INC. 11951 FREEDOM DRIVE, 6TH FLOOR RESTON VA 20190 1 1 0 0 Chief Executive Officer Common Stock 2022-08-15 4 F 0 27386 22.86 D 3329263 D Common Stock 340691 I See footnote Common Stock 144185 I See footnote This transaction is not a sale of shares by the Reporting Person. Instead, the shares were withheld by the Issuer, to satisfy withholding taxes in connection with the vesting on August 15, 2022 of restricted stock units held by the Reporting Person. Shares held of record by the Kevin R. Mandia 2011 Irrevocable Trust Dated July 29, 2011 (the "Irrevocable Trust"). The Reporting Person's spouse, as trustee, has shared voting and investment power with respect to the shares held of record by the Irrevocable Trust. The Reporting Person disclaims beneficial ownership of such shares. Shares held of record by the Reporting Person's spouse. The Reporting Person disclaims beneficial ownership of the shares held by his spouse, and this report should not be deemed an admission that the Reporting Person is the beneficial owner of his spouse's shares for purpose of Section 16 or for any other reason. Richard Meamber, Attorney-in-Fact 2022-08-17