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Exhibit 10.27

SIXTH LOAN MODIFICATION AGREEMENT

        This Sixth Loan Modification Agreement (this "Agreement") is entered
into as of January 12, 2005 by and between WITNESS SYSTEMS, INC., a Delaware
corporation ("Borrower"), whose address is 300 Colonial Center Parkway, Roswell,
Georgia 30076, and SILICON VALLEY BANK ("Lender"), a California-chartered bank
with a principal place of business at 3003 Tasman Drive, Santa Clara, CA 95054
and with a loan production office located at 3353 Peachtree Road, Suite M-10,
Atlanta, GA 30326.

        WHEREAS, among other indebtedness which may be owing by Borrower to
Lender, Borrower is indebted to Lender pursuant to, among other documents, a
Loan and Security Agreement, dated April 3, 2002, as may be amended from time to
time, in the original principal amount of Fifteen Million Dollars ($15,000,000)
(the "Loan Agreement"; the Loan Agreement together with all other documents
evidencing or securing the indebtedness shall be referred to as the "Existing
Loan Documents");

        WHEREAS, the Loan Agreement provides for, among other things, a
Committed Revolving Line in the original principal amount of Fifteen Million
Dollars ($15,000,000) (hereinafter, all indebtedness owing by Borrower to Lender
shall be referred to as the "Indebtedness"); and

        WHEREAS, Borrower has requested that Lender amend the Loan Agreement,
and Lender is willing to do so, subject to the terms and conditions set forth
herein.

        NOW, THEREFORE, in consideration of the foregoing premises, and other
good and valuable consideration, the receipt and legal sufficiency of which is
hereby acknowledged, the parties hereto hereby agree as follows:

(a)DEFINITIONS.    All capitalized terms used herein and not otherwise defined
shall have the meanings given to such terms in the Loan Agreement.

(b)MODIFICATIONS TO LOAN AGREEMENT.    The Loan Agreement is hereby amended as
follows:

(i)Financial Covenant.    The Loan Agreement is hereby amended by deleting
Section 6.7(ii) thereof in its entirety and by substituting therefor a new
Section 6.7(ii) to read as follows:

(ii)EBITDA.    Quarterly EBITDA, averaged for period of the fiscal quarter then
ending and immediately preceding three fiscal quarters, of not less than the
amount set forth below with respect to each such fiscal quarter end:

Fiscal Quarter Ending:

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  Average EBITDA

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  March 31, 2005   $ (500,000 ) June 30, 2005   $ 1,500,000   September 30, 2005
  $ 3,000,000   December 31, 2005   $ 4,000,000  

(ii)Tangible Net Worth Definition.    The Loan Agreement is hereby further
amended by deleting the definition of "Tangible Net Worth" in its entirety.

(iii)EBITDA Definition.    The Loan Agreement is hereby further amended by
adding, in appropriate alphabetical order, a new definition of "EBITDA" to read
as follows:

"EBITDA" is, for any period of determination thereof, net income before
interest, taxes, depreciation, amortization expense and non-cash compensation
expense, all as determined in accordance with GAAP.

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(c)CONSENT TO ACQUISITION.    Pursuant to Section 7.3 of the Loan Agreement,
Lender hereby consents to the merger of Baron Acquisition Corporation, a
wholly-owned subsidiary of Borrower ("Merger Sub"), with and into Blue Pumpkin
Software, Inc. ("Blue Pumpkin"), with Blue Pumpkin as the surviving corporation
and a wholly-owned subsidiary of Borrower (the "Merger"), on the terms set forth
in the Merger Agreement and Plan of Reorganization dated December 16, 2004 (the
"Merger Agreement") among Borrower, Blue Pumpkin, Merger Sub and, solely with
respect to Article VIII and Article IX, Laurence R. Hootnick as shareholder
Agent and The U.S. Stock Transfer Corporation, as Depository Agent. Borrower
agrees that it shall (a) deliver to Lender, within forty-five (45) days after
the consummation of the Merger, updated closing date balance sheets for the
Borrower and its Subsidiaries as of the date of the Merger, together with
undated projected financial statements for 2005, in each case giving effect to
the Merger and (b) if requested by Lender, negotiate with Lender in good faith
to amend the financial covenants and other provisions of the Loan Documents in
order to reflect such updated balance sheets and projected financial statements.

(d)CONSISTENT CHANGES.    The Existing Loan Documents are hereby amended
wherever necessary to reflect the changes described above.

(e)NO DEFENSES OF BORROWER.    Borrower agrees that it has no defenses against
the obligations to pay any amounts under the Indebtedness.

(f)CONTINUING VALIDITY.    Borrower understands and agrees that in modifying the
existing Indebtedness, Lender is relying upon Borrower's representations,
warranties, and agreements, as set forth in the Existing Loan Documents. Except
as expressly modified pursuant to this Agreement, the terms of the Existing Loan
Documents remain unchanged and in full force and effect. Lender's agreement to
modifications to the existing Indebtedness pursuant to this Agreement in no way
shall obligate Lender to make any future modifications to the Indebtedness.
Nothing in this Agreement shall constitute a satisfaction of the Indebtedness.
It is the intention of Lender and Borrower to retain as liable parties all
makers and endorsers of Existing Loan Documents, unless the party is expressly
released by Lender in writing. No maker, endorser, or guarantor will be released
by virtue of this Agreement. The terms of this paragraph apply not only to this
Agreement, but also to all subsequent loan modification agreements.

(g)EXPENSES.    Borrower shall reimburse Lender for all out-of-pocket expenses,
including, but not limited to, reasonable attorneys' fees and expenses, incurred
by Lender in connection with this Agreement.

(h)NEGATIVE PLEDGE.    Borrower and Lender are parties to that certain Negative
Pledge Agreement, dated as of April 3, 2002 (the "Negative Pledge Agreement").
Borrower hereby acknowledges and agrees that the Negative Pledge Agreement, and
Borrower's obligations thereunder, remain in full force and effect, without
release, diminution or impairment, notwithstanding the execution and delivery of
this Agreement.

(i)LIMITATION.    This Agreement is limited to the matters expressly set forth
above and shall not be deemed to waive or modify any other term of the Loan
Agreement or Loan Documents, each of which is hereby ratified and reaffirmed, or
to consent to any subsequent failure of Borrower to comply with any term or
provision of the Loan Agreement or the Loan Documents, each of which shall
remain in full force and effect.

(j)CONDITIONS.    The effectiveness of this Agreement is conditioned upon:
(a) Borrower's execution and delivery of this Agreement, (b) Borrower's payment
of all outstanding legal fees and expenses and (c) such other instruments,
documents and agreements as Lender or its counsel shall request.

[signatures appear on following page]

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        This Loan Modification Agreement is executed as of the date first
written above.

    LENDER:
 
 
SILICON VALLEY BANK
 
 
By:
 
          

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    Name:             

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    Title:             

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BORROWER:
 
 
WITNESS SYSTEMS, INC.
 
 
By:
 
          

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    Name:             

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    Title:             

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SIXTH LOAN MODIFICATION AGREEMENT