North America

Exhibit 10.15

AMENDMENT TO INVESTOR RIGHTS AGREEMENT

     THIS AMENDMENT TO INVESTOR RIGHTS AGREEMENT (this “Amendment”) is entered into as of December 29, 2006 (the “Amendment Date”), by and among TrustWave Holdings, Inc., a Delaware corporation (the “Company”), and the persons signatory hereto (the “Signatories”).

RECITALS

     WHEREAS, the Company and its stockholders are parties to that certain Investor Rights Agreement, dated as of March 14, 2005 (the “Original Agreement”); and

     WHEREAS, all capitalized terms used in this Amendment which are not defined herein shall have the respective meanings assigned to them in the Original Agreement; and

     WHEREAS, the Signatories constitute the holders of at least a majority of the Registrable Securities; and

     WHEREAS, the parties hereto desire to amend the Original Agreement as provided in this Amendment.

     NOW, THEREFORE, in consideration of the foregoing recitals and the mutual promises, representations, warranties, covenants and conditions contained in this Amendment and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, agree as follows:

     1. Addition of Common Stockholders. The stockholders listed on the attached Exhibit C are hereby constituted as Common Stockholders for all purposes of the Original Agreement, as amended by this Amendment.

     2. Certain Definitions. The following definition contained in the Original Agreement is hereby amended to read, in its entirety, as follows:

     “Major Common Stockholder” means a Common Stockholder who, on the Amendment Date and at the date of determination, holds Registrable Securities representing at least 100,000 shares of Common Stock.

     3. No Other Amendments. Except as expressly amended by this Amendment, all of the terms and provisions of the Original Agreement shall remain in full force and effect.

     4. Counterparts. This Amendment may be executed by facsimile and in counterparts, each of which shall be an original, but all of which together shall constitute one instrument.

[Signature Page Follows]

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed as of the Amendment Date.

		COMPANY:
		TRUSTWAVE HOLDINGS, INC.
		By:		/s/ Robert J. McCullen
				Name:		Robert J. McCullen
				Title:		Chief Executive Officer
		STOCKHOLDERS:
		Financial Technology Ventures II (Q), L.P.
		By:		Financial Technology Management II, LLC
		By:		/s/ Richard N. Garman
				Name:		Richard N. Garman
				Title:		Managing Member
		Financial Technology Ventures II, L.P.
		By:		Financial Technology Management II, LLC
		By:		/s/ Richard N. Garman
				Name:		Richard N. Garman
				Title:		Managing Member
		/s/ Richard Kiphart
		Richard Kiphart
		/s/ David Valentine
		David Valentine
		/s/ Joseph L. Patanella
		Joseph L. Patanella
SIGNATURE PAGE TO INVESTOR RIGHTS AGREEMENT

		/s/ Phillip J. Smith
		Phillip J. Smith
		Caledonian Investments, L.P.
		By:		/s/ Tim Nicholson
				Name:		Tim Nicholson
				Title:		Caledonian Corp. General Partner
		The Nicholson Family Limited Partnership
		By:		/s/ Tim Nicholson
				Name:		Tim Nicholson
				Title:		General Partner
		MBK Ventures, LLC
		By:		/s/ Robert McCullen
				Name:		Robert McCullen
				Title:		Manager
		[SECUREPIPE HOLDERS]

SIGNATURE PAGE TO INVESTOR RIGHTS AGREEMENT

		ARGENTUM CAPITAL PARTNERS II, L.P.
		By: Argentum Partners II, L.L.C.
				By:		/s/ Walter Barandiaran-
				Its:
		PRISM OPPORTUNITY FUND IV, L.P.
		By: POF Partners SBIC, Inc., its General Partner
				By:		/s/ Robert A. Funkel
				Its:		President
		THE PRODUCTIVITY FUND IV, L.P.
		By: First Analysis Management Company IV,
		L.L.C., its General Partner
		By: First Analysis Venture Operations and
		Research, L.L.C., its Member
		By: First Analysis Corporation, its Manager
				By:		/s/ Howard S. Smith
		THE PRODUCTIVITY FUND IV ADVISORS
		FUND, L.P.
		By: First Analysis Management Company IV,
		L.L.C., its General Partner
		By: First Analysis Venture Operations and
		Research, L.L.C., its Member
		By: First Analysis Corporation, its Manager
				By:		/s/ Howard S. Smith
		FA PRIVATE EQUITY FUND IV, L.P.
		By: FA Private Equity Management IV, L.L.C., its
		General Partner
		By: First Analysis Private Equity Management
		Company IV, L.L.C., its Managing Member
		By: First Analysis Venture Operations and
		Research, L.L.C., its Managing Member
		By: First Analysis Corporation, its Manager
				By:		/s/ Howard S. Smith

		/s/ Marvin Lader
		Marvin Lader
		/s/ James Macdonald
		James Macdonald
		/s/ Arch Moesta
		Arch P. Moesta
		/s/ Dan Sterling
		Dan Sterling
		/s/ Susan Sterling
		Susan Sterling
		/s/ Art Roldan
		Art Roldan
		/s/ Lawrence Levine
		Lawrence Levine
		/s/ Lawrence Levine
		Comet Capital LLC
		Lawrence Levine, Manager
		Maxwell Guy and Cynthia Diane Morgan
		Revocable Trust dated November 15, 2002
				By:		/s/ Maxwell Guy
		Georgy Milliken, Trustee Milliken Family Trust
				By:		/s/ George Miliken
		/s/ Michael Kiefer
		Michael Kiefer

EXHIBIT C

List of SecurePipe Common Holders