<PAGE>
EXECUTION COPY                                                    EXHIBIT 10.4.2

                           FIRST FEDERAL OF THE SOUTH

                        GUARANTY OF EMPLOYMENT AGREEMENT

                                 OCTOBER 1, 2001

                               (J. MALCOMB MASSEY)

                  THIS AGREEMENT to guarantee and provide certain payments and
obligations under an employment agreement (the "Guaranty") is entered into, as
of the first day of October, 2001 (the "Effective Date"), by and among
SouthFirst Bancshares, Inc. ("SouthFirst'), First Federal of the South (the
"Bank"), Pension & Benefit Financial Services, Inc., f/k/a "Benefit Financial
Services, Inc.," (the "Company") and J. Malcomb Massey (the "Employee").

WHEREAS, in April, 1997, the Company was acquired by SouthFirst, the sole
shareholder of the Bank; and

WHEREAS, upon the grant of limited trust powers from the Office of Thrift
Supervision to the Bank, on September 9, 1998, to be exercised by and through
the Company, as the operating subsidiary of the Bank, SouthFirst, in September,
1998, transferred the ownership of the Company to the Bank; and

WHEREAS, upon such transfer, the Company became the wholly-owned operating
subsidiary of the Bank; and

WHEREAS, the Employee is president and chief executive officer of the Company, a
position he has held since he joined the Company in April, 1997, immediately
following the acquisition by the Company of substantially all of the assets of
Lambert, Massey, Roper & Taylor, Inc., an employee benefits consulting firm
based in Montgomery, Alabama, for which the Employee had served as President
since 1980; and

WHEREAS, the Company and the Employee, in April, 1997, entered into that certain
employment agreement, which was amended and restated as of October 1, 2001, and
as may be hereafter amended (the "Employment Agreement"); and

WHEREAS, it was the intent of the parties hereto, to provide assurances to the
Employee regarding the performance of each obligation of the Company provided
for, and specified in, the Employment Agreement, or amended from time to time;

                  NOW, THEREFORE, it is AGREED as follows:

         1.       SouthFirst and the Bank hereby agree that, to the extent
permitted by law, and subject to the terms and conditions of the Employment
Agreement, each of them shall be jointly and severally liable, with each other
and with the Company, for the payment of all amounts due to the
<PAGE>

Employee under the Employment Agreement and for the performance of all
obligations of the Company to, or on behalf of, the Employee under the
Employment Agreement.

         2.       In the event that any dispute arises between the Employee and
the Bank and/or SouthFirst, as to the terms or interpretation of this Guaranty,
whether instituted by formal legal proceedings or otherwise, including any
action that the Employee takes to enforce the terms of this Guaranty or to
defend against any action taken by the Bank and/or SouthFirst, the Employee
shall be reimbursed for all costs and expenses, including reasonable attorneys'
fees, arising from such dispute, proceedings or actions, provided that the
Employee shall have obtained a final judgement by a court of competent
jurisdiction in favor of the Employee. Such reimbursement shall be paid within
ten (10) days of Employee's furnishing to the Bank and/or SouthFirst appropriate
written evidence of any costs or expenses incurred by the Employee, which
evidence may be in the form, among other things, of a canceled check or receipt.

         3.       This Guaranty shall inure to the benefit of, and be binding
upon, any successor of the Bank and/or SouthFirst which shall acquire, directly
or indirectly, by merger, consolidation, purchase or otherwise, all or
substantially all of the assets or stock of the Bank and/or SouthFirst.

         4.       No amendments or additions to this Guaranty shall be binding
unless made in writing and signed by each of the parties.

         5.       The laws of the State of Alabama shall govern this Guaranty in
all respects, whether as to its validity, construction, capacity, performance or
otherwise.

         6.       The provisions of this Guaranty shall be deemed severable and
the invalidity or unenforceability of any provision shall not affect the
validity or enforceability of the other provisions hereof.

         7.       This Guaranty, together with any understanding or
modifications thereof, as agreed to in writing by the parties, shall constitute
the entire agreement between the parties with respect to subject thereof.
Further, should any provision of this Guaranty give rise to a discrepancy or
conflict with respect to any applicable law or regulation, then the applicable
law or regulation shall control the relevant construction and operation of this
Guaranty.



                            [EXECUTION PAGE FOLLOWS]


                                       -2-
<PAGE>

                  IN WITNESS WHEREOF, the parties have executed this Guaranty,
as of the day and year first hereinabove written.


ATTEST:                               "SouthFirst"
                                      SOUTHFIRST BANCSHARES, INC.



                                      BY:
-------------------------------          --------------------------------------
Secretary                                Its:
                                             ----------------------------------


ATTEST:                               "Bank"
                                      FIRST FEDERAL OF THE SOUTH



                                      BY:
-------------------------------          --------------------------------------
Secretary                                Its:
                                             ----------------------------------


ATTEST:                               "Company"
                                      PENSION & BENEFIT FINANCIAL
                                      SERVICES, INC.



                                      BY:
-------------------------------          --------------------------------------
Secretary                                Its:
                                             ----------------------------------


WITNESS:                              "Employee"
                                      J. MALCOMB MASSEY



-------------------------------       -----------------------------------------
                                      J. Malcomb Massey


                                       -3-