North America

Exhibit 10.52

SIXTH AMENDMENT TO INVESTOR RIGHTS AGREEMENT

     THIS SIXTH AMENDMENT TO INVESTOR RIGHTS AGREEMENT (this “Sixth Amendment”) is entered into as of August __, 2011 (the “Sixth 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, as amended through the date hereof (as so amended, the “Original Agreement”); and

     WHEREAS, all capitalized terms used in this Sixth 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 Sixth Amendment.

     NOW, THEREFORE, in consideration of the foregoing recitals and the mutual promises, representations, warranties, covenants and conditions contained in this Sixth 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. For all purposes of the Original Agreement, as amended by this Sixth Amendment, each stockholder listed on the attached Schedule 1 is hereby constituted as a Common Stockholder and, so long as on the date of determination such stockholder holds Registrable Securities representing at least 100,000 shares of Common Stock, a Major Common Stockholder.

     2. Information and Reporting. Without limiting the foregoing, each stockholder listed on the attached Schedule 1 shall be entitled to the benefits of Sections 3.1 and 3.2 of the Original Agreement, subject to the limitations contained in Sections 3.3 and 3.7 of the Original Agreement, so long as such stockholder is a Major Investor and continues to hold at least ten percent (10%) of the total number of shares of capital stock (as adjusted for stock splits and on an as-converted basis) held by such stockholder on the Sixth Amendment Date.

     3. Joinder. By executing this Sixth Amendment, each stockholder listed on the attached Schedule 1 agrees that it shall succeed to all of the obligations of a Common Stockholder, Major Common Stockholder and/or Major Investor as contemplated by the Original Agreement, as amended by this Sixth Amendment.

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

     5. Counterparts. This Sixth 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.

(SIGNATURES ON NEXT PAGES)

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

		COMPANY:
		TRUSTWAVE HOLDINGS, INC.
		By:
				Name: Robert McCullen
				Title: Chief Executive Officer

		STOCKHOLDERS:
		Financial Technology Ventures II (Q), L.P.
		Financial Technology Ventures II, L.P.
		By:		Financial Technology Management, II, LLC
		By:
				Name:
				Title:
		Richard Kiphart
		David Valentine

Signature Page to Sixth Amendment to Investor Rights Agreement

		DBRC Investments, LLC.
		By:
				Name:
				Title:
		Phillip J. Smith
		MBK Ventures, LLC
		By:
				Name: Robert McCullen
				Title: Manager

Signature Page to Sixth Amendment to Investor Rights Agreement

		Caledonia Investments, L.P.
		By:
				Name: Tim Nicholson
				Title: Managing Director
		Nicholson Acquisitions LP
		By:
				Name: Tim Nicholson
				Title: General Partner

Signature Page to Sixth Amendment to Investor Rights Agreement

		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:
				Howard S. Smith, Managing Director
		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:
				Howard S. Smith, Managing Director
		FA PRIVATE EQUITY FUND IV, L.P.
		By:		FA Private Equity Management IV, L.C.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:
				Howard S. Smith, Managing Director

Signature Page to Sixth Amendment to Investor Rights Agreement

		FA PRIVATE EQUITY FUND IV GMBH & CO. BETEILIGUNGS KG
		By:		FA Private Equity Management IV, L.C.C.,
				its Managing Limited 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:
				Howard S. Smith, Managing Director

Signature Page to Sixth Amendment to Investor Rights Agreement

		SRBA #5, L.P.
		By:		Hallman Management Trust, its General Partner
		By:
				Trustee

Signature Page to Sixth Amendment to Investor Rights Agreement

		Bullseye Securities, LLC
		By:
				Name:
				Title:

Signature Page to Sixth Amendment to Investor Rights Agreement

		Venture Lending & Leasing IV, LLC
		By:
				Name:
				Title:

Signature Page to Sixth Amendment to Investor Rights Agreement

		William Bertrand, Jr.
		Stuart Harvey
		Walter Hosp
		L. Neil Hunn
		Zachary Nelson
		Ruth Ann Marshall
		Kevin Bradford

Signature Page to Sixth Amendment to Investor Rights Agreement

		FTVentures III, L.P.
		FTVentures III-N, L.P.
		FTVentures III-T, L.P.
		By:		FTVentures Management III, LLC
		By:
				Name:
				Title:

Signature Page to Sixth Amendment to Investor Rights Agreement

SCHEDULE 1

Bullseye Securities, LLC

Venture Lending & Leasing IV, LLC

William Bertrand, Jr.

Stuart Harvey

Walter Hosp

L. Neil Hunn

Zachary Nelson

Ruth Ann Marshall

Kevin Bradford

FTVentures III, L.P.

FTVentures III-N, L.P.

FTVentures III-T, L.P.