`(10) Patent N0.:
`US 6,804,780 B1
`
`Touboul
`(45) Date of Patent:
`*Oct. 12, 2004
`
`U5006804780Bl
`
`(54) SYSTEM AND METHOD FOR PROTECTING
`A COMPUTER AND A NETWORK FROM
`HOSTILE DOWNLOADABLES
`,
`~
`_
`,
`,
`«
`,
`anentor.
`Shlomo Touboul, Ketar haim (IL)
`(75)
`.
`.
`.
`(73) A551g11ee: Finjan Software, Ltd., Netanya (IL)
`.
`.
`.
`.
`.
`( * ) Notlce:
`Subject to any dlsclaimer, the term of this
`$123111 if5:)((ff)nfied( 91f adjusted under 35
`. ‘.C.
`s
`y )
`ays.
`
`This patent is subject to a terminal dis—
`claimer.
`
`0.:
`
`pp .
`(21) A 1 N
`(22) Filed:
`
`,
`09/539 667
`Mar. 30, 2000
`
`Related U.S. Application Data
`
`(60)
`
`(63) Continuation of application No. 08/964,388, filed on Nov. 6,
`1997, now Pat. No. 6,092,194.
`Provisional application No. 60/030,639, filed on Nov. 8,
`1996.
`I t C] 7
`(51)
`Il .
`.
`_
`,
`(52) U.S. Cl.
`
`H04L 9/00 G06F 11/30
`............................
`;
`....................... 713/181; 713/201; 713/176;
`717/178
`
`(58) Field Of Searglli3..1.%6...1.81. 76502397215333)? 335’
`’
`/
`’
`/‘
`’ “ 71’77] 6:3 ‘17,;
`’
`‘ _
`‘
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`5,077,677 A
`5,359,659 A
`5,361,359 A
`5,485,409 A
`5,485,575 A
`
`12/1991 Murphy et a].
`10/1994 Rosenthal
`11/1994 Tajalli et a1.
`1/1996 Gupta et al.
`1/1996 Chess et a].
`
`............... 703/27
`
`11/1996 Judson
`5,572,643 A
`5,579,509 A * 11/1996 Eurtney et a1.
`3,606,668 A
`24997 filmed
`5,623,600 A
`4/1997 J1 et a1.
`5,638,446 A
`6/1997 Rubin
`5;6929047 A
`11/1997 McManis
`5,692,124 A
`111997 H ld
`t
`5,720,033 A
`2/1998 D20 en 6 a
`‘ ‘24 425 A
`3 1998 Ch
`1.
`5,740,248 A
`4/1998 “6:15 :51.
`5:761:421 A
`6/1998 van Hoff et al.
`(List continued on next page.)
`FOREIGN PA'l‘EN’l‘ DOCUMENTS
`1091276 A1 *
`4/2001
`............. (306F/1/00
`
`l.
`
`............. G06F/1/00
`9/2001
`1132796 A1 “
`OTHER PUBLICATIONS
`
`El’
`
`EP
`
`Khare, “Microsoft Authentieode Analyzed” Jul. 22, 1996,
`xent.com/FoRK—archive/summer96/O338html, p, 1—2.*
`
`(List conthEd on nCXt page.)
`.
`,
`.
`,
`.
`Fri/nary anmtrier—Ayaz. bhmkh
`Asszsttmt Examiner—Christopher Revak
`(74) Attorney, Agent,
`or Firm$quire, Sanders &
`Dempsey, LWLP
`
`(57)
`ABSTRACT
`A computer-based method for generating a Downloadable
`ID to identify a Downloadable, including obtaining a Down—
`loadable that includes one or more references to software
`
`components required by the Downloadable, fetching at least
`one software component
`identified by the one or more
`references, and performing a function on the Downloadable
`and the fetched software components to generate a Down—
`loadable ID. A system and a computer-readable storage
`medium are also described and claimed.
`
`18 Claims, 10 Drawing Sheets
`
`800
`
`(J
`
`810
`
`31311
`
`Receive a Downtoadabte
`
`v
`
`'
`Ietch Downloadable
`f
`Components
`—v_, ,
`The Downtoadabte
`
`Include Fetched onmpnnems m //
`
`e40
`,
`the Downloadabte tc Generate
`Perform a Hashing Function on //
`a Eownlaadable D
`850
`,/
`
`/_/
`820
`J
`
`530
`
`
`
`
`
`
`
`v
`Store the annlnadahte ID
`
`
`End
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0001
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0001
`
`
`
`US 6,804,780 Bl
`
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`................ 717/171
`
`6/1998 Breslau et al.
`5,765,205 A
`7/1998 Devarakonda et al.
`5,784,459 A
`8/1998 Davis et a1.
`5,796,952 A
`9/1998 Cohen et a].
`5,805,829 A
`11/1998 Chen et al.
`5,832,208 A
`5,832,274 A * 11/1998 Cutler et a1.
`5,850,559 A
`12/1998 Angelo et al.
`5,859,966 A
`1/1999 Hayman et al.
`5,864,683 A
`1/1999 Boebert et :1].
`5,892,904 A
`4/1999 Atkinson et 211.
`5,951,698 A
`9/1999 Chen et al.
`5,956,481 A
`9/1999 Walsh et 211.
`5,974,549 A
`10/1999 Golan
`5,978,484 A * 11/1999 Apperson et a].
`5,983,348 A
`11/1999 Ji
`..................... 713/200
`6,092,194 A *
`1’2000 Touboul
`
`6,154,844 A * 11/2000 Touboul et al.
`713/201
`............... 713/201
`6,339,829 B1
`1/2002 Beadle et al.
`OTHER PUBLICATIONS
`
`............. 705/54
`
`“Release Notes for the Microsfot ActiveX Development
`Kit”, Aug. 13, 1996, aetiveX.adsp.or.jp/inetsdk/readrne.txt,
`p. 1—10.*
`“Microsoft ActiveX Software Development Kit” Aug. 12,
`1996,
`activex.adsp.or.jp/'inetsdk/help/overview.htm,
`p.
`1—6.*
`Doyle et al, “Microsoft Press Computer Dictionary” 1993,
`Microsoft Press, 2nd Edition, p. 137—138.>g
`Schmitt, “.EXE. files, OS72 style” Nov. 1988, PC Tech
`Journal via dialog search, vol. 6, #11, p. 76—78.*
`Jim K. Omura, “Novel Applications of Cryptography in
`Digital Communications”, IEEE Communications Maga-
`zine, May, 1990; pp. 21—29.
`Okamoto, E. et al., “IDiBased Authentication System For
`Computer Virus Detection”, IEEE/IEE Electronic Library
`online, Electronics Letters, vol. 26, Issue 15, ISSN 0013/
`5194, Jill. 19, 1990, Abstract and pp. 1169—1170. URL:
`http://iel.ihs.com:80/cgi7bin/ie1icgi?se
`.
`2ehts%26ViewTemplate%3ddocview%5fb%2ehts.
`IBM AntiVirus User’s Guide Version 2.4, International
`Business Machines Corporation, Nov. 15, 1995, pp. 6—7.
`
`Norvin Leach et al, “IE 3.0 Applets Will Earn Certification”,
`PC Week, vol. 13, No. 29, Jul. 22, 1996, 2 pages.
`“Finjan Software Releases SurfinBoard, Industry‘s First
`JAVA Security Product For the World Wide Web”, Article
`published on the Internet by Finjan Softwre Ltd., Jul. 29,
`1996, 1 page.
`“Powerful PC Security for the New World of JavaTM and
`Downloadables, Surfin ShieldTM” Article published on the
`Internet by Finjan Software Ltd., 1996, 2 Pages.
`Microsoft® Authenticode Technology, “Ensuring Account—
`ability and Authenticity for Software Components on the
`Internet”, Microsoft Corporation, Oct. 1996,
`including
`Abstract, Contents, Introduction and pp. 1—10.
`“Finjan Announces a Personal JavaTM Firewall For Web
`Browsersithe SurfinShieldTM 1.6 (formerly known as Surf—
`inBoard)”, Press Release of Finjan Releases SurfinShield
`1.6, Oct. 21, 1996, 2 pages.
`Company Profile “Finjan—Safe Surfing, The Java Security
`Solutions Provider”, Article published on the Internet by
`Finjan Software Ltd., Oct. 31, 1996, 3 pages.
`“Finjan Announces Major Power Boost and New Features
`for SurfinShieldTM 2.0” Las Vegas Convention Center/Pa-
`vilion 5 P5551, Nov. 18, 1996, 3 pages.
`“Java Security: Issues & Solutions” Article published on the
`Internet by Finjan Software Ltd., 1996, 8 pages.
`“Products” Article published on the Internet, 7 pages.
`Mark LaDue, “Online Business Consulant: Java Security:
`Whose Business Is It?" Article published on the Internet,
`Home Page Press, Inc. 1996, 4 pages.
`Web Page Article “Frequently Asked Questions About
`Authenticode”, Microsoft Corporation, last updated Feb. 17,
`1997, Printed Dec. 23, 1998. URL: http://wwwmicrosoft.
`com/workshop/security/authcode/signfaq.asp#9, pp. 1—13.
`Zhang, X.N., “Secure Code Distribution”, IEEE/IEE Elec-
`tronic Library online, Computer, vol. 30, Issue 6, Jun, 1997,
`pp. 76—79.
`
`* cited by examiner
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0002
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0002
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 1 0f 10
`
`US 6,804,780 B1
`
`100
`
`105
`
`
`External Computer Network
`
`Internal Network
`
`Security System
`
`Internal Computer Network
`
`
`
`
`
`120
`
`Security
`Management
`Console
`
`
`
`
`
`FIG. 1
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0003
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0003
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 2 0f 10
`
`US 6,804,780 B1
`
`NOE
`
`mmN
`
`0mm
`
`o:
`
`\K.
`
`Eoi
`
`
`
`LquEoo.mEmzxm
`
`mowx8382
`
`mvm
`
`EN
`
`mom
`
`
`
`ONN
`
` \
`
`38:95o:
`
`mcozmoEzEEoo
`
`moatBE
`
`.mEmem
`
`Duo
`
`
`
`Bcsomm
`
`Emhmoi
`
`mczfimao
`
`E996
`
`
`
`
`
`
`i
`
`
`
`QVN
`mvm
`owm
`
`
`
`
`mo;mEmSm
`
`
`
`@9805Ema
`
`83mm
`
`b:somw
`
`mmmnfimo
`
`mcozmoEsEEoo
`
`SEE:
`
`_mEmE_
`
`8.
`
`
`
`559:00:9:me
`
`
`
`m:{9562
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0004
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0004
`
`
`
`
`
`
`
`
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 3 0f 10
`
`US 6,804,780 B1
`
`oom
`
`ovm
`
`m:o_oam:mcoz_
`mfimvmoEsoo”
`
`__
`
`mmm
`
`_mu_mo._
`
`mEmcm
`
`28mm
`
`mcfiwmx
`
`mEEm
`
`mvm
`
`._o<
`
`Bumfiano
`
`$00
`
`mecmow
`
`985:8
`
`Loyfiquoo
`
`v,5mm
`
`.ED
`
`hoymLmQEoo
`
`ovm
`
`285:8
`
`mecmow
`
`ommnEmS
`
`
`
`mi6:89
`
`
`
`
`
`LESmano59:;58850
`
`Jan
`
`.95w:
`
`328mm
`
`mfimuonioD
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0005
`
`mom
`
`mom
`
`\
`
`orm
`
`no
`
`Eman50
`
`
`
`wm_o__on_bczowm
`
`860550Esocxmwzmumozioo555.T\u\
`
`
`
` $338@585_
`
`
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0005
`
`
`
`
`
`
`
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 4 0f 10
`
`US 6,804,780 B1
`
`Security Policies
`
`305
`
`/
`
`
`
`4:.
`
`Policy Selectors
`
`i___
`
`
`
`
`
`Access Control
`
`Lists
`
`Trusted
`
`Certificate Lists
`
`URL Rule Bases
`
`o0..o0"
`
`425
`
`
`
`
`
`
`Lists of Downloadabies
`
`to Allow or Block per
`Administrative Override
`
`
`
`
`
`
`FIG. 4
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0006
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0006
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 5 0f 10
`
`US 6,804,780 B1
`
`120
`
`To/From
`
`Internal Computer
`Network
`
`135
`
`
`
`510
`
`Security
`Event Log
`
`
`Analysts
`.
`.
`.
`Policy Editor
`
`
`Engine
`
`
`
`User
`
`515
`
`Notification
`
`
`
`
`
`Engine
`
`
`
`FIG. 5
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0007
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0007
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 6 0f 10
`
`US 6,804,780 B1
`
`600
`
`R
`
`6‘14
`
`
`URL
`
`
`comparison
`
`required?
`616
`
`Compare URL
`
`
`
`ACL
`comparison
`
`required?
`
`Yes
`626
`
`602
`
`604
`
`606
`
`Receive Downloadable
`
`Generate Downloadable ID
`
`
`
` Find Security Policy
`
`608
`
`Yes
`
`610
`
`Yes
`
`Downloadable
`allowed?
`
`No
`
`
`
`Downloadable
`blocked?
`
`
`No
`
`No
`
`618
`
`NO
`
`
`
`620
`
`
`TCL
`No
`
`comparison
`required?
`
`622
`Yes /
`Scan Certificate
`
`1
`
`Yes
`
`
` Previously
`decomposed
`7
`628
`
`NO
`
`\D
`
`ecompose Downloadable
`into DSP data
`
`Compare Certificate
`with TCL
`
`Compare DSP with ACL
`
`630
`
`FIG. 6A
`
`/
`624
`
`
`
`
`Send results to
`Logical Engine
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0008
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0008
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 7 0f 10
`
`US 6,804,780 B1
`
`606
`
`/
`
`Security policy defined
`for User—ID and
`Downloadable?
`
`
`
`
`
`
`Fetch the generic
`security policy for
`
`User ID
`
`
`
`
`Fetch the policy
`for
`User ID and
`Downloadable
`
`End
`
`FIG. BB
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0009
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0009
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 8 0f 10
`
`US 6,804,780 B1
`
`655
`
`/
`
`670
`
`Receive Results from First
`
`
`
`Comparator, ACL
`Comparator, Certificate
`
`Comparator and URL
`Comparator
`
`650
`
`66
`
`2
`
`Compare Results with
`Security Policies
`
`
`
`Security Policies
`Confirm Pass?
`
`’
`I Yes
`Pass Downloadable
`
`664
`
`N0
`
`666
`
`Stop Downloadable /
`
`672
`
`Send Substitute /
`
`Downloadbie to
`
`
`
`668
`
`Inform The User
`
` Record Findings
`
`FIG. 6C
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0010
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0010
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 9 0f 10
`
`US 6,804,780 B1
`
`628
`
`H
`
`Disassemble the Machine
`Code
`
`Resolve a Respective
`Command in The Code
`
`
`
`Is The Resolved
`
`Command Suspect?
`
`Decode and Register The
`Command and The
`
`Command Parameters as
`DSP Data
`
`FIG. 7
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0011
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0011
`
`
`
`US. Patent
`
`Oct. 12, 2004
`
`Sheet 10 0f 10
`
`US 6,804,780 B1
`
`800
`
`/
`
`
`
`
`
`Receive 23 Downloadable
`
`8‘10
`
`820
`
`
`
`Fetch Downloadabie
`
`Components
`
`830
`
`
`InCIude Fetched Components in
`The Downloadable
`
`
`840
`
`
`
`Perform a Hashing Function on
`the Downloadable to Generate
`21 Downloadable ID
`
`
`
`
`i
`
`850
`
`Store the Downloadable ID
`
`End
`
`FIG. 8
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0012
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0012
`
`
`
`US 6,804,780 B1
`
`1
`SYSTEM AND METHOD FOR PROTECTING
`A COMPUTER AND A NETWORK FROM
`HOSTILE DOWNLOADABLES
`
`PRIORITY REFERENCE TO RELATED
`APPLICATION
`
`This application is a continuation of and hereby incorpo-
`rates by reference US. patent application Ser. No. 08/964,
`388, entitled “System and Method for Protecting a Com-
`puter and a Network from Hostile Downloadables,” filed
`Nov. 6, 1997, which is now US. Pat. No. 6,092,194, which
`claims priority to provisional application Serial No. 60/030,
`639, entitled “System and Method for Protecting a Com-
`puter from Hostile Downloadables,” filed on Nov. 8, 1996,
`by inventor Shlomo Touboul.
`INCORPORATION BY REFERENCE TO
`RELATED APPLICATIONS
`
`This application hereby incorporates by reference related
`US. patent application Ser. No. 08/790,097, entitled “Sys-
`tem and Method for Protecting a Client from Hostile
`Downloadables,” filed on Jan. 29, 1997, which is now US.
`Pat. No. 6,167,520, by inventor Shlomo Touboul; and
`hereby incorporates by reference provisional application
`Ser. No. 60/030,639, entitled “System and Method for
`Protecting a Computer from Hostile Downloadables,” filed
`on Nov. 8, 1996, by inventor Shlomo Touboul.
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`
`This invention relates generally to computer networks,
`and more particularly provides a system and method for
`protecting a computer and a network from hostile Down-
`loadables,
`
`U\
`
`10
`
`15
`
`,
`
`3O
`
`2. Description of the Background Art
`The Internet is currently a collection of over 100,000
`individual computer networks owned by governments,
`universities, nonprofit groups and companies, and is expand-
`ing at an accelerating rate. Because the Internet is public, the
`Internet has become a major source of many system dam—
`aging and system fatal application programs, commonly
`referred to as “Viruses.”
`Accordingly, programmers continue to design computer
`and computer network security systems for blocking these
`viruses from attacking both individual and network com-
`puters. On the most part, these security systems have been
`relatively successful. However, these security systems are
`not configured to recognize computer Viruses which have
`been attached to or configured as Downloadable application
`programs, commonly referred to as “Downloadables.” A 7
`Downloadable is an executable application program, which
`is downloaded from a source computer and run on the
`destination computer. Downloadable is typically requested
`by an ongoing process such as by an Internet browser or web
`engine. Examples of Downloadables include JavaTM applets
`designed for use in the JavaTM distributing environment
`developed by Sun Microsystems, Inc., JavaScript scripts
`also developed by Sun Microsystems, Inc., ActiveXTM con-
`trols designed for use in the ActiveXTM distributing envi-
`ronment developed by the Microsoft Corporation, and
`Visual Basic also developed by the Microsoft Corporation.
`Therefore, a system and method are needed to protect a
`network from hostile Downloadables.
`SUMMARY OF THE INVENTION
`
`35
`
`40
`
`6O
`
`65
`
`The present invention provides a system for protecting a
`network from suspicious Downloadables. The system com-
`
`2
`prises a security policy, an interface for receiving a
`Downloadable, and a comparator, coupled to the interface,
`for applying the security policy to the Downloadable to
`determine if the security policy has been violated. The
`Downloadable may include a JavaTM applet, an ActiveXTM
`control, a JavaScriptTM script, or a Visual Basic script. The
`security policy may include a default security policy to be
`applied regardless of the client to whom the Downloadable
`is addressed, a specific security policy to he applied based on
`the client or the group to which the client belongs, or a
`specific policy to be applied based on the client/group and on
`the particular Downloadable received. The system uses an
`ID generator to compute a Downloadable ID identifying the
`Downloadable, preferably, by fetching all components of the
`Downloadable and performing a hashing function on the
`Downloadable including the fetched components.
`Further, the security policy may indicate several tests to
`perform, including (1) a comparison with known hostile and
`non-hostile Downloadables; (2) a comparison with Down-
`loadables to be blocked or allowed per administrative over-
`ride; (3) a comparison of the Downloadable security profile
`data against access control
`lists; (4) a comparison of a
`certificate embodied in the Downloadable against trusted
`certificates; and (5) a comparison of the URL from which the
`Downloadable originated against
`trusted and untrusted
`URI .s. Based on these tests, a logical engine can determine
`whether to allow or block the Downloadable.
`
`invention further provides a method for
`The present
`protecting a computer from suspicious Downloadables. The
`method comprises the steps of receiving a Downloadable,
`comparing the Downloadable against a security policy to
`determine if the security policy has been violated, and
`discarding the Downloadable if the security policy has been
`violated.
`
`It will be appreciated that the system and method of the
`present invention may provide computer protection from
`known hostile Downloadables. The system and method of
`the present
`invention may identify Downloadables that
`perform operations deemed suspicious. The system and
`method of the present invention may examine the Down-
`loadable code to determine whether the code contains any
`suspicious operations, and thus may allow or block the
`Downloadable accordingly.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a block diagram illustrating a network system,
`in accordance with the present invention;
`FIG. 2 is a block diagram illustrating details of the
`internal network security system of FIG. 1;
`FIG. 3 is a block diagram illustrating details of the
`security program and the security database of FIG. 2;
`FIG. 4 is a block diagram illustrating details of the
`security policies of FIG. 3;
`FIG. 5 is a block diagram illustrating details of the
`security management console of FIG, 1;
`FIG. 6A is a flowchart illustrating a method of examining
`for suspicious Downloadables,
`in accordance with the
`present invention;
`FIG. 6B is a flowchart illustrating details of the step for
`finding the appropriate security policy of FIG. 6A;
`FIG. 6C is a flowchart illustrating a method for determin-
`ing whether an incoming Downloadable is to be deemed
`suspicious,
`FIG. 7 is a flowchart illustrating details of the FIG. 6 step
`of decomposing a Downloadable, and
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0013
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0013
`
`
`
`US 6,804,780 B1
`
`3
`illustrating a method 800 for
`FIG. 8 is a flowchart
`generating a Downloadable ID for identifying a Download-
`able.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`FIG. 1 is a block diagram illustrating a network system
`100, in accordance with the present invention. The network
`system 100 includes an external computer network 105,
`such as the Wide Area Network (WAN) commonly referred
`to as the Internet, coupled Via a communications channel
`125 to an internal network security system 110. The network
`system 100 further includes an internal computer network
`115, such as a corporate Local Area Network (LAN),
`coupled via a communications channel 130 to the internal
`network computer system 110 and coupled via a communi-
`cations channel 135 to a security management console [20.
`The internal network security system 110 examines
`Downloadables received from external computer network
`105, and prevents Downloadables deemed suspicious from
`reaching the internal computer network 115.
`It will be
`further appreciated that a Downloadable is deemed suspi—
`cious if it performs or may perform any undesirable
`operation, or if it threatens or may threaten the integrity of
`an internal computer network 115 component. It is to be
`understood that
`the term “suspicious” includes hostile,
`potentially hostile, undesirable, potentially undesirable, etc.
`Security management console 120 enables viewing, modi-
`fication and configuration of the internal network security
`system 110.
`FIG. 2 is a block diagram illustrating details of the
`internal network security system 110, which includes a
`Central Processing Unit (CPU) 205, such as an Intel Pen-
`tium® microprocessor or
`a Motorola Power PC®
`microprocessor, coupled to a signal bus 220. The internal
`network security system 110 further includes an external
`communications interface 210 coupled between the com-
`munications channel 125 and the signal bus 220 for receiv—
`ing Downloadables from external computer network 105,
`and an internal communications interface 225 coupled
`between the signal bus 220 and the communications channel
`130 for forwarding Downloadables not deemed suspicious
`to the internal computer network 115. The external commu—
`nications interface 210 and the internal communications
`interface 225 may be functional components of an integral
`communications interface (not shown) for both receiving
`Downloadables from the external computer network 105 and
`forwarding Downloadables to the internal computer network
`115.
`
`Internal network security system 110 further includes
`Input/Output (I/O)
`interfaces 215 (such as a keyboard,
`mouse and Cathode Ray Tube (CRT) display), a data storage
`device 230 such as a magnetic disk, and a Random-Access
`Memory (RAM) 235, each coupled to the signal bus 220.
`The data storage device 230 stores a security database 240,
`which includes security information for determining
`whether a received Downloadable is to be deemed suspi-
`cious. The data storage device 230 further stores a users list
`260 identifying the users within the internal computer net—
`work 115 who may receive Downloadables, and an event log
`245 which includes determination results for each Down-
`loadable examined and runtime indications of the internal
`network security system 110. An operating system 250
`controls processing by CPU 205, and is typically stored in
`data storage device 230 and loaded into RAM 235 (as
`illustrated) for execution. A security program 255 controls
`
`U\
`
`10
`
`15
`
`30
`
`35
`
`4o
`
`60
`
`65
`
`4
`examination of incoming Downloadables, and also may be
`stored in data storage device 230 and loaded into RAM 235
`(as illustrated) for execution by CPU 205.
`FIG. 3 is a block diagram illustrating details of the
`security program 255 and the security database 240. The
`security program 255 includes an ID generator 315, a policy
`finder 317 coupled to the ID generator 315, and a first
`comparator 320 coupled to the policy finder 317. The first
`comparator 320 is coupled to a logical engine 333 via four
`separate paths, namely, via Path 1, via Path 2, Via Path 3 and
`via Path 4. Path 1 includes a direct connection from the first
`comparator 320 to the logical engine 333. Path 2 includes a
`code scanner coupled to the first comparator 320, and an
`Access Control List (ACL) comparator 330 coupling the
`code scanner 325 to the logical engine 333. Path 3 includes
`a certificate scanner 340 coupled to the first comparator 320,
`and a certificate comparator 345 coupling the certificate
`scanner 340 to the logical engine 333. Path 4 includes a
`Uniform Resource Locator (URL) comparator 350 coupling
`the first comparator 320 to the logical engine 3330. A
`record-keeping engine 335 is coupled between the logical
`engine 333 and the event log 245.
`The security program 255 operates in conjunction with
`the security database 240, which includes security policies
`305, knoan Downloadables 307, known Certificates 309
`and Downloadable Security Profile (DSP) data 310 corre-
`sponding to the known Downloadables 307. Security poli-
`cies 305 includes policies specific to particular users 260 and
`default (or generic) policies for determining whether to
`allow or block an incoming Downloadable. These security
`policies 305 may identify specific Downloadables to block,
`specific Downloadables to allow, or necessary criteria for
`allowing an unknown Downloadable. Referring to FIG. 4,
`security policies 305 include policy selectors 405, access
`control lists 410, trusted certificate lists 415, URL rule bases
`420, and lists 425 of Downloadables to allow or to block per
`administrative override.
`Known Downloadables 307 include lists of Download-
`
`ables which Original Equipment Manufacturers (OEMs)
`know to be hostile, of Downloadables which OEMs know to
`be non—hostile, and of Downloadables previously received
`by this security program 255. DSP data 310 includes the list
`of all potentially hostile or suspicious computer operations
`that may be attempted by each known Downloadable 307,
`and may also include the respective arguments of these
`operations. An identified argument of an operation is
`referred to as “resolved.” An unidentified argument
`is
`referred to as “unresolved.” DSP data 310 is described below
`with reference to the code scanner 325.
`
`The ID generator 315 receives a Downloadable (including
`the URL from which it came and the userID of the intended
`recipient) from the external computer network 105 via the
`external communications interface 210, and generates a
`Downloadable ID for identifying each Downloadable, The
`Downloadable ID preferably includes a digital hash of the
`complete Downloadable code. The ID generator 315 pref—
`erably prefetches all components embodied in or identified
`by the code for Downloadable ID generation. For example,
`the ID generator 315 may prefetch all classes embodied in
`or identified by the JavaTM applet bytecode to generate the
`Downloadable ID. Similarly,
`the ID generator 315 may
`retrieve all components listed in the INF file for an
`ActiveXTM control
`to compute a Downloadable ID.
`Accordingly, the Downloadable ID for the Downloadable
`will be the same each time the ID generator 315 receives the
`same Downloadable. The ID generator 315 adds the gener-
`ated Downloadable ID to the list of known Downloadables
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0014
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0014
`
`
`
`US 6,804,780 B1
`
`5
`307 (if it is not already listed). The ID generator 315 then
`forwards the Downloadable and Downloadable ID to the
`policy finder 317.
`The policy finder 317 uses the userID of the intended user
`and the Downloadable ID to select
`the specific security
`policy 305 that shall be applied on the received Download-
`able. If there is a specific policy 305 that was defined for the
`user (or for one of its super groups) and the Downloadable,
`then the policy is selected. Otherwise the generic policy 305
`that was defined for the user (or for one of its super groups)
`is selected. The policy finder 317 then sends the policy to the
`first comparator 320.
`The first comparator 320 receives the Downloadable, the
`Downloadable ID and the security policy 305 from the
`policy finder 317. The first comparator 320 examines the
`security policy 305 to determine which steps are needed for
`allowing the Downloadable. For example,
`the security
`policy 305 may indicate that,
`in order to allow this
`Downloadable, it must pass all four paths, Path 1, Path 2,
`Path 3 and Path 4. Alternatively, the security policy 305 may
`indicate that to allow the Downloadable, the it must pass
`only one of the paths. The first comparator 320 responds by
`forwarding the proper information to the paths identified by
`the security policy 305.
`
`Path 1
`
`the first comparator 320 checks the policy
`In path 1,
`selector 405 of the security policy 305 that was received
`from the policy finder 317. If the policy selector 405 is either
`“Allowed” or “Blocked,” then the first comparator 320
`forwards this result directly to the logical engine 333.
`Otherwise, the first comparator 320 invokes the comparisons
`in path2 and/or path 3 and/or path 4 based on the contents
`of policy selector 405. It will be appreciated that the first
`comparator 320 itself compares the Downloadable ID
`against the lists of Downloadables to allow or block per
`administrative override 425. That is, the system security
`administrator can define specific Downloadables as
`“Allowed” or “Blocked.”
`
`the logical engine 333 may receive the
`Alternatively,
`results of each of the paths and based on the policy selector
`405 may institute the final determination whether to allow or
`block the Downloadable. The first comparator 320 informs
`the logical engine 333 of the results of its comparison.
`Path 2
`
`the first comparator 320 delivers the
`In path 2,
`Downloadable, the Downloadable ID and the security policy
`305 to the code scanner 325. If the DSP data 310 of the
`received Downloadable is known,
`the code scanner 325
`retrieves and forwards the information to the ACI. compara-
`tor 330. Otherwise, the code scanner 325 resolves the DSP
`data 310. That is, the code scanner 325 uses conventional
`parsing techniques to decompose the code (including all
`prefetched components) of the Downloadable into the DSP
`data 310. DSP data 310 includes the list of all potentially
`hostile or suspicious computer operations that may be
`attempted by a specific Downloadable 307, and may also
`include the respective arguments of these operations. For
`example, DSP data 310 may include a READ from a specific
`file, a SEND to an unresolved host, etc. The code scanner
`325 may generate the DSP data 310 as a list of all operations
`in the Downloadable code which could ever be deemed
`potentially hostile and a list of all files to be accessed by the
`Downloadable code. It will be appreciated that the code
`scanner 325 may search the code for any pattern, which is
`undesirable or suggests that
`the code was written by a
`hacker.
`
`U\
`
`10
`
`15
`
`30
`
`35
`
`40
`
`.
`
`6O
`
`65
`
`6
`An Example List of Operations Deemed Potentially
`Hostile
`
`File operations: READ a file, WRITE a file;
`Network operations: LISTEN on a socket, CONNECT to
`a socket, SEND data, RECEIVE data, VIEW INTRA-
`NET;
`Registry operations: READ a registry item, WRITE a
`registry item;
`Operating system operations: EXIT WINDOWS, EXIT
`BROWSER, START PROCESS/THREAD, KILL
`PROCESS/THREAD, CHANGE PROCESS/
`THREAD PRIORITY, DYNAMICALLY LOAD A
`CLASS/LIBRARY, etc.; and
`Resource usage thresholds: memory, CPU, graphics, etc.
`In the preferred embodiment, the code scanner 325 performs
`a full-content inspection. However, for improved speed but
`reduced security, the code scanner 325 may examine only a
`portion of the Downloadable such as the Downloadable
`header. The code scanner 325 then stores the DSP data into
`DSP data 310 (corresponding to its Downloadable ID), and
`sends the Downloadable, the DSP data to the ACL com-
`parator 330 for comparison with the security policy 305.
`The ACL comparator 330 receives the Downloadable, the
`corresponding DSP data and the security policy 305 from the
`code scanner 325, and compares the DSP data against the
`security policy 305. That
`is,
`the ACL comparator 330
`compares the DSP data of the received Downloadable
`against the access control lists 410 in the received security
`policy 305. The access control list 410 contains criteria
`indicating whether to pass or fail the Downloadable. For
`example, an access control list may indicate that the Down—
`loadable fails if the DSP data includes a WRITE command
`to a system file. The ACL comparator 330 sends its results
`to the logical engine 333.
`
`Path 3
`
`In path 3, the certificate scanner 340 determines whether
`the received Downloadable was signed by a certificate
`authority, such as VeriSign, Inc., and scans for a certificate
`embodied in the Downloadable. The certificate scanner 340
`forwards the found certificate to the certificate comparator
`345. The certificate comparator 345 retrieves known certifi-
`cates 309 that were deemed trustworthy by the security
`administrator and compares the found certificate with the
`known certificates 309 to determine whether the Download—
`able was signed by a trusted certificate. The certificate
`comparator 345 sends the results to the logical engine 333.
`Path 4
`
`ln path 4, the URL comparator 350 examines the URL
`identifying the source of the Downloadable against URLs
`stored in the URL rule base 420 to determine whether the
`Downloadable comes from a trusted source. Based on the
`security policy 305, the URL comparator 350 may deem the
`Downloadable suspicious if the Downloadable comes from
`an untrustworthy source or if the Downloadable did not
`come from a trusted source. For example, if the Download—
`able comes from a known hacker, then the Downloadable
`may be deemed suspicious and presumed hostile. The URL
`comparator 350 sends its results to the logical engine 333.
`The logical engine 333 examines the results of each of the
`paths and the policy selector 405 in the security policy 305
`to determine whether to allow or block the Downloadable.
`The policy selector 405 includes a logical expression of the
`results received from each of the paths. For example, the
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0015
`
`SOPHOS
`EXHIBIT 1014 - PAGE 0015
`
`
`
`US 6,804,780 B1
`
`7
`logical engine 333 may block a Downloadable if it fails any
`one of the paths, i.e., if the Downloadable is known hostile
`(Path 1), if the Downloadable may request suspicious opera-
`tions (Path 2), if the Downloadable was not signed by a
`trusted certificate authority (Path 3), or if the Downloadable
`did came from an untrustworthy source (Path 4). The logical
`engine 333 may apply other logical expressions according to
`the policy selector 405 embodied in the security policy 305.
`If the policy selector 405 indicates that the Downloadable
`may pass, then the logical engine 333 passes the Download-
`able to its intended recipient. Otherwise,
`if the policy
`selector 405 indicates that
`the Downloadable should be
`blocked, then the logical engine 333 forwards a non—hostile
`Downloadable to the intended recipient to inform the user
`that
`internal network security system 110 discarded the
`original Downloadable. Further,
`the logical engine 333
`forwards a status report to the record—keeping engine 335,
`which stores the reports in event log 245 in the data storage
`device 230 for subsequent review, for example, by the MIS
`director.
`
`FIG. 5 is a block diagram illustrating details of the
`security management console [20