<PAGE>

                          SEE REVERSE FOR RESTRICTIONS


     No. D-                       CYNET, INC.                            Shares

                                 PREFERRED STOCK


                INCORPORATED UNDER THE LAWS OF THE STATE OF TEXAS


THIS CERTIFIES THAT                SPECIMEN


IS THE OWNER OF

FULLY PAID AND NON-ASSESSABLE SHARES OF SERIES D REDEEMABLE CONVERTIBLE
PREFERRED STOCK, NO PAR VALUE, OF

CYNET, INC., A CORPORATION ORGANIZED IN THE STATE OF TEXAS, TRANSFERABLE ON
THE BOOKS OF THE CORPORATION BY THE HOLDER HEREOF, IN PERSON OR BY DULY
AUTHORIZED ATTORNEY UPON SURRENDER OF THIS CERTIFICATE PROPERLY ENDORSED.
THIS CERTIFICATE AND THE SHARES REPRESENTED HEREBY ARE ISSUED AND SHALL BE
HELD SUBJECT TO ALL OF THE PROVISIONS OF THE ARTICLES OF INCORPORATION OF THE
CORPORATION, AS AMENDED, AND THE BYLAWS OF THE CORPORATION, AS AMENDED,
COPIES OF WHICH ARE ON FILE AT THE PRINCIPAL OFFICE OF THE CORPORATION, TO
ALL OF WHICH THE HOLDER OF THIS CERTIFICATE ASSENTS BY ACCEPTANCE HEREOF.

IN WITNESS WHEREOF, THE CORPORATION HAS CAUSED THIS CERTIFICATE TO BE SIGNED
BY ITS DULY AUTHORIZED OFFICERS AND ITS CORPORATE SEAL TO BE HERETO AFFIXED.

Dated:



-----------------------------------    ----------------------------------------


<PAGE>

                                  CYNET, INC.

         THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR
INVESTMENT AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, OR THE SECURITIES LAWS OF ANY STATE. EXCEPT UPON SUCH REGISTRATION,
SUCH SHARES MAY NOT BE SOLD OR TRANSFERRED AT ANY TIME WHATSOEVER EXCEPT UPON
DELIVERY TO THE CORPORATION OF AN OPINION OF COUNSEL SATISFACTORY TO THE
CORPORATION THAT REGISTRATION IS NOT REQUIRED FOR SUCH TRANSFER AND/OR
SUBMISSION TO THE CORPORATION OF SUCH OTHER EVIDENCE AS MAY BE SATISFACTORY TO
THE CORPORATION TO THE EFFECT THAT ANY SUCH TRANSFER SHALL NOT BE IN VIOLATION
OF THE SECURITIES ACT OF 1933, AS AMENDED, AND/OR APPLICABLE STATE SECURITIES
LAWS AND/OR ANY RULE OR REGULATION PROMULGATED THEREUNDER.

STATEMENT REGARDING AUTHORIZED SHARES OF MORE THAN ONE CLASS AND NOTICE OF
DENIAL OF PREEMPTIVE RIGHTS.

         FULL STATEMENTS OF THE DESIGNATION, PREFERENCES, LIMITATIONS AND
RELATIVE RIGHTS OF THE SHARES OF EACH CLASS OF AUTHORIZED STOCK OF THE
CORPORATION, THE VARIATIONS IN THE RELATIVE RIGHTS AND PREFERENCES OF THE SHARES
OF ANY SERIES OF PREFERRED STOCK SO FAR AS THE SAME HAVE BEEN FIXED AND
DETERMINED, AND THE AUTHORITY OF THE BOARD OF DIRECTORS TO FIX AND DETERMINE THE
RELATIVE RIGHTS AND PREFERENCES OF EACH SERIES THEREOF, AND OF THE DENIAL OF THE
PREEMPTIVE RIGHTS OF SHAREHOLDERS TO ACQUIRE UNISSUED OR TREASURY SHARES OF THE
CORPORATION, ARE SET FORTH IN THE ARTICLES OF INCORPORATION OF THE CORPORATION,
AS AMENDED, WHICH ARE ON FILE IN THE OFFICE OF THE SECRETARY OF THE STATE OF
TEXAS, COPIES OF WHICH MAY BE OBTAINED, WITHOUT CHARGE ON WRITTEN REQUEST TO THE
CORPORATION AT ITS PRINCIPAL PLACE OF BUSINESS OR REGISTERED OFFICE.

         THE FOLLOWING ABBREVIATIONS, WHEN USED IN THE INSCRIPTION ON THE FACE
OF THIS CERTIFICATE, SHALL BE CONSTRUED AS THOUGH THEY WERE WRITTEN OUT IN FULL
ACCORDING TO APPLICABLE LAW OR REGULATION:
TEN COM - AS TENANTS IN COMMON
TEN ENT - AS TENANTS BY THE ENTIRETIES
JT TEN - AS JOINT TENANTS WITH RIGHT OF SURVIVORSHIP AND NOT AS TENANTS IN
         COMMON.

UNIF GIFT MIN ACT-                        CUSTODIAN
                  -----------------------           ----------------------------
                           (CUST)                               (MINOR)
                          UNDER UNIFORM GIFTS TO MINORS ACT
                                                             -------------------
                                                                    (STATE)
UNIF TRF MIN ACT-                         CUSTODIAN (UNTIL AGE __)
                  -----------------------                         --------------
                           (CUST)                                      (MINOR)
                          UNDER UNIFORM TRANSFER TO MINOR ACT
                                                              ------------------
                                                                    (STATE)
       ADDITIONAL ABBREVIATIONS MAY ALSO BE USED THOUGH NOT IN ABOVE LIST.

FOR VALUE RECEIVED,                        HEREBY SELL, ASSIGN AND TRANSFER UNTO
                   -----------------------

                  PLEASE INSERT SOCIAL SECURITY NUMBER OR OTHER
                         IDENTIFYING NUMBER OF ASSIGNEE

--------------------------------------------------------------------------------
  (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS INCLUDING ZIP CODE OF ASSIGNEE)


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--------------------------------------------------------------------------------

                        SHARES OF THE CAPITAL STOCK REPRESENTED BY THE WITHIN
-----------------------
CERTIFICATE, AND DO HEREBY IRREVOCABLY CONSTITUTE AND APPOINT
                                                              ------------------
ATTORNEY TO TRANSFER THE SAID STOCK ON THE BOOKS OF THE WITHIN NAMED CORPORATION
WITH FULL POWER OF SUBSTITUTION IN THE PREMISES.

DATED
      ----------------------------

            NOTICE:

THE SIGNATURE(S) TO THIS ASSIGNMENT MUST   X
CORRESPOND WITH THE NAME(S) AS WRITTEN ON    -----------------------------------
THE FACE OF THE CERTIFICATE IN EVERY                     (SIGNATURE
PARTICULAR WITHOUT ALTERATION OR
ENLARGEMENT OR ANY CHANGE WHATEVER.        X
                                             -----------------------------------
                                                         (SIGNATURE)

                                             -----------------------------------
                                             THE SIGNATURE(S) SHOULD BE
                                             GUARANTEED BY AN ELIGIBLE
                                             GUARANTOR INSTITUTION (BANKS,
                                             STOCKBROKERS, SAVINGS AND
                                             LOAN ASSOCIATIONS AND CREDIT
                                             UNIONS WITH MEMBERSHIP IN AN
                                             APPROVED SIGNATURE GUARANTEE
                                             MEDALLION PROGRAM.)

                                             -----------------------------------

                                             SIGNATURE(S) GUARANTEED BY: