       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                 ______________________

                  SOPHOS LIMITED,
                      Appellant

                            v.

    ANDREI IANCU, UNDER SECRETARY OF
  COMMERCE FOR INTELLECTUAL PROPERTY
   AND DIRECTOR OF THE UNITED STATES
     PATENT AND TRADEMARK OFFICE,
                  Intervenor
            ______________________

                       2017-1567
                 ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2015-
01405.
                 ______________________

                 Decided: March 28, 2018
                 ______________________

    STANLEY JOSEPH PANIKOWSKI, III, DLA Piper LLP
(US), San Diego, CA, argued for appellant. Also repre-
sented by SEAN C. CUNNINGHAM, KATHRYN RILEY GRASSO.

    MOLLY R. SILFEN, Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
intervenor. Also represented by NATHAN K. KELLEY,
2                                   SOPHOS LIMITED   v. IANCU



SARAH E.     CRAVEN,    THOMAS     W.   KRAUSE,    WILLIAM
LAMARCA.
                 ______________________

    Before PROST, Chief Judge, O’MALLEY, and TARANTO,
                      Circuit Judges.
TARANTO, Circuit Judge.
    In this inter partes review, Finjan Holdings, Inc. chal-
lenged various claims of Sophos Limited’s U.S. Patent
No. 8,776,218, which describes and claims computer
programs that perform runtime behavior-based detection
of malicious software. The Patent Trial and Appeal Board
of the Patent and Trademark Office (PTO) determined
that certain claims are unpatentable for obviousness.
Sophos appeals from the Board’s decision. With Finjan no
longer participating, the PTO’s Director has intervened.
Because the Board’s claim construction, as the Board
understood its scope, is incorrect, we vacate the Board’s
decision and remand for further proceedings.
                             I
                             A
     The ’218 patent relates to a computer program that
monitors “an executing computer process” for “indica-
tion[s] of malicious behavior,” takes “[a] plurality of
malicious behavior indications observed” in the executing
computer process and compares that observed collection
to one or more “predetermined collection[s] of malicious
behaviors” in a database of such collections, and, if there
is a “match[],” conducts further analysis and causes action
to be taken. ’218 patent, Abstract. The particular claim
phrase at issue here involves assigning a “rank” to a
predetermined collection of malicious behaviors, relative
to other collections. Doing so can help determine the
threat level when the observed set of malicious behaviors
in the executing computer process is found to match a
SOPHOS LIMITED   v. IANCU                                  3



particular predetermined collection of malicious behav-
iors. See ’218 patent, col. 18, lines 26–30, col. 24, lines
10–14.
    Malicious software (malware) can take various forms
such as “virus, worm, spam, phishing exploration, spy-
ware, [and] adware.” Id., col. 3, lines 19–23. The patent
describes using two kinds of databases for malware
detection. Each element in one database is a predeter-
mined malicious behavior referred to as a “gene,” which
may be identified in an executing computer process being
monitored. Id., col. 1, lines 46–50. The patent gives
examples of genes (malicious behaviors), such as disabling
operating system tools, disabling a firewall, adding itself
to firewall lists, copying itself to a system folder, and
opening a hidden file. Id., col. 2, lines 16–24. Each
element in the other database is a predetermined collec-
tion of such genes, each such collection referred to as a
“phenotype.” Id., col. 1, lines 52–56. A phenotype may be
any combination of such behaviors—in particular, “a
predetermined collection of malicious behaviors which
may include a grouping of specific genes that are typically
present in a type or family of malicious code.” Id., col. 18,
lines 18–21; col. 1, lines 54–56.
     The patent describes the process of testing an execut-
ing or other program—a “runtime object” in the case of an
executing program—by gathering observed indications of
malicious behavior (genes) in the program, comparing a
plurality of such indications to the phenotypes in the
phenotype database, and “causing an action based on a
prediction that the executing computer process is the type
of malicious code as indicated by the phenotype.” Id., col.
1, lines 56–58; see id., col. 18, lines 22–25 (stating that a
monitoring component “may be able to identify a pheno-
type of behaviors in an executing code by comparing a
collection of observed behaviors with the predetermined
collections of known malicious behaviors stored as pheno-
types in a phenotype database”). What is sought in the
4                                    SOPHOS LIMITED   v. IANCU



comparison is a “match.” Id., Abstract; col. 17, lines 41–
48, 61–65. The patent explains the benefits: “Matching
this runtime genotype data with known combinations
stored in the phenotype database, with or without addi-
tional content analysis, may enable the identification and
interruption of malware while it is executing.” Id., col. 17,
lines 41–45 (figure numbers omitted). “By matching
combinations of behaviors in this way, detection of mal-
ware may be improved over solutions where only singular
behaviors and a static content analysis is utilized.” Id.,
col. 17, lines 45–48.
    The patent specification contains one mention of
“rank[ing].” It says: “Phenotypes may capture a combina-
tion or a series of behaviors that may be ranked to create
increasing levels of confidence that the runtime object
being monitored is executing a behavior pattern compara-
ble to a known family of malware.” Id., col. 18, lines 26–
30.
     During prosecution of the patent, in response to a re-
jection, Sophos amended its claims to add language
specifically about ranking, not previously recited in the
claims. J.A. 116, 120. Both in the language of the inde-
pendent claims, see infra p. 5 (quoting claim 1) and in its
explanation accompanying the amendment, Sophos made
clear that it is each phenotype (each one a “combination
or a series of behaviors,” ’218 patent, col. 18, line 27) that
is “ranked,” so that matching one phenotype rather than
another can provide more information about the likely
malware threat of the runtime object being tested. So-
phos explained:
    [P]henotypes are created and ranked to provide
    increasing levels of confidence that a runtime ob-
    ject is executing a behavior pattern comparable to
    a known family of malware. A content analysis is
    then performed only after detected malicious be-
    havior indications correspond to a phenotype hav-
SOPHOS LIMITED   v. IANCU                                 5



   ing a predetermined level of confidence that the
   computer process contains a known family of
   malware. In this manner, the applicant’s tech-
   nique includes a progression from phenotype de-
   tection to content analysis based on a likelihood of
   malware. Claim 1 has been amended to clarify
   this inventive concept.
J.A. 120.
    The Board and the parties treat claim 1 as repre-
sentative. It reads:
   A computer program product embodied in a non-
   transitory computer readable medium that, when
   executing on one or more computers, performs the
   steps of:
     monitoring an executing computer process for
      an indication of malicious behavior, wherein
      the indication of the malicious behavior is a
      result of comparing an operation with a prede-
      termined behavior, referred to as a gene,
      where the gene is stored for reference in a da-
      tabase and wherein the gene relates to at
      least one of API calls, registry access, process
      manipulation, and file system access;
     performing the monitoring step a number of
       times to collect a plurality of malicious behav-
       ior indications;
     comparing the plurality of malicious behavior
       indications to a predetermined collection of
       malicious behaviors, referred to as a pheno-
       type, which comprises a grouping of specific
       genes that are typically present in a type of
       malicious code, and wherein the phenotype is
       one of a number of phenotypes that are ranked
       to create increasing levels of confidence that a
6                                    SOPHOS LIMITED   v. IANCU



         runtime object is executing a behavior pattern
         comparable to a known family of malware;
        triggering a content analysis of the executing
          computer process when the plurality of mali-
          cious behavior indications for the executing
          computer process corresponds to one of the
          number of phenotypes having a predeter-
          mined level of confidence that the executing
          computer process contains a known family of
          malware, thereby providing a prediction that
          the executing computer process is the type of
          malicious code; and
        causing an action based on the prediction.
’218 patent, col. 23, line 60 through col. 24, line 24 (em-
phasis added). Claim 11 depends on claim 1, and claim 12
contains an identical “wherein . . . are ranked” clause in
its comparing step. Id., col. 24, lines 65–67; col. 25, lines
1–23.
                              B
    Finjan petitioned for an inter partes review of claims
1 through 20 under 35 U.S.C. §§ 311–19. The Board,
acting as the delegate of the PTO’s Director under 37
C.F.R. § 42.4(a), instituted a review of claims 1, 11, and
12 on multiple grounds, all under 35 U.S.C. § 103. Finjan
Holdings, Inc. v. Sophos Ltd., IPR2015-01405, Paper No.
9, at 27 (P.T.A.B. Dec. 15, 2015) (Institution Decision). 1
The Board decided to review claims 1 and 12 for obvious-
ness over U.S. Patent No. 7,809,670 (Lee) and U.S. Patent



    1   The ’218 patent, which issued from a 2009 appli-
cation, is governed by the version of § 103 that was in
effect before the provision’s amendment by the Leahy-
Smith America Invents Act, Pub. L. No. 112-29, § 3(n)(1),
125 Stat. 284, 293 (2011).
SOPHOS LIMITED   v. IANCU                                  7



No. 8,171,545 (Cooley), and also over U.S. Patent
No. 7,089,428 (Farley) and Cooley. Id. The Board decided
to review claim 11 for obviousness over Lee, Cooley, and
U.S. Application No. 2007/0240217 (Tuvell) and also over
Farley, Cooley, and Tuvell. Id.
    In its Final Written Decision, the Board construed the
claim phrase requiring that phenotypes “are ranked.”
Finjan Holdings, Inc. v. Sophos Ltd., IPR2015-01405,
2016 WL 7987957, at *4–6 (P.T.A.B. Nov. 30, 2016) (Final
Written Decision). The Board first construed the term
“ranked” to mean simply “ordered,” id. at *4, meaning
that the phenotypes must be ordered vis-à-vis each other.
The Board then concluded that, in the phrase “are
ranked,” ranking “may occur as part of the comparing
step such that phenotypes are not ‘already ranked’” before
the comparing step begins. Id. at *6 (emphasis added).
    The “may” in that conclusion, however, ultimately
does not accurately reflect the Board’s understanding of
“are ranked.” As the key substantive basis for its claim
construction, the Board explained its understanding of
the claimed ranking in a way that actually precludes pre-
comparison ranking. Specifically, the Board said that
“[a]s a result of the comparison, the phenotypes ‘are
ranked’”; “[i]t is only in the context of the comparison that
the ranking occurs”; and “[t]he reason for the comparison
between the ‘malicious behavior indications’ and the
‘phenotypes’ is to identify the most problematic pheno-
type, which is ‘ranked’ according to how similar it is to the
‘executing computer program.’” Id. at *5 (emphases add-
ed). In short, the Board’s understanding is that the
invention ranks phenotypes based on their similarity to a
particular runtime object being examined. The Director
confirms that this is the Board’s construction and that the
8                                 SOPHOS LIMITED   v. IANCU



construction necessarily precludes pre-comparison rank-
ing. Director’s Br. 1–2. 2
    The Board then applied that understanding. Using
that similarity-based understanding, it found that both
Lee and Farley disclosed the “are ranked” limitation.
Final Written Decision, 2016 WL 7987957, at *14, *18–19.
And, as a result, it held that claims 1, 11, and 12 are
unpatentable for obviousness. Id. at *20.
    Sophos timely appealed the Board’s decision under 35
U.S.C. §§ 141(c) and 319. Finjan declined to participate
in this appeal, and the PTO’s Director intervened, pursu-
ant to 35 U.S.C. § 143, to defend the Board’s decision.
Appellee’s Notice of Non-Participation, ECF No. 12 (Apr.
4, 2017); Notice of Intervention by the United States
Patent and Trademark Office, ECF No. 18 (May 17, 2017).
We have jurisdiction under 28 U.S.C. § 1295(a)(4)(A).
                            II
    Sophos argues that the Board, in construing the rank-
ing limitation, misunderstood what “are ranked” means in
the context of the claims. More specifically, Sophos
contends that the Board was wrong in its fundamental
view that the predetermined phenotypes, which are stored
in the database, are ranked based on how similar they are
to the set of malicious behavior indications observed in a
particular monitored runtime object (program). The only


    2   The Director states that “[t]he Board construed
the term ‘are ranked’ to mean ranking while the compari-
son is happening” and that the issue presented is: “Did
the Board reasonably construe ‘are ranked,’ where the
known collections of behaviors do not have a natural
order, or ranking, except with respect to how similar they
are to the unknown program, and that similarity cannot
be known until the comparison is occurring?” Director’s
Br. 1–2 (emphasis added).
SOPHOS LIMITED   v. IANCU                                 9



reasonable understanding of the claim phrase, Sophos
says, is quite different: a phenotype is ranked relative to
others based in some way on its indicating known mal-
ware; the runtime object is scrutinized to see if its set of
observed behaviors matches one of the phenotypes in the
phenotype database; and it is the rank of a matched
phenotype that determines the level of confidence that the
runtime object is like a known family of malware (trigger-
ing content analysis and action). We agree with Sophos.
    The Board reached its conclusion regarding the scope
of its claim construction on the basis of its degree-of-
similarity-to-runtime-object understanding of the “are
ranked” limitation. Final Written Decision, 2016 WL
7987957, at *5. On appeal, the Director defends the
Board’s construction of the “are ranked” limitation on that
basis, stating that “the ranking is done during the
claimed process to determine which phenotype most
closely corresponds to a particular unknown program.”
Director’s Br. 15. At oral argument, the Director effec-
tively agreed that we may address the correctness of this
basis for the Board’s adoption of the claim construction
challenged by Sophos. 3
    In an inter partes review proceeding, the Board is to
give a claim “its broadest reasonable construction in light
of the specification of the patent in which it appears.” 37
C.F.R. § 42.100(b); see Cuozzo Speed Techs., LLC v. Lee,
136 S. Ct. 2131, 2142 (2016) (affirming the PTO’s authori-
ty to prescribe such a standard). “We review the Board’s
constructions based on intrinsic evidence de novo.” HTC


   3     See Oral Argument at 19:47–23:45, 24:21–25:10,
Sophos Ltd. v. Iancu, No. 17-1567 (Fed. Cir. Mar. 9, 2018),
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
17-1567.mp3 (agreeing that the Board’s construction was
based on its understanding of ranking and that the
Board’s understanding may be reviewed in this appeal).
10                                  SOPHOS LIMITED   v. IANCU



Corp. v. Cellular Commc’ns Equip., LLC, 877 F.3d 1361,
1367 (Fed. Cir. 2017). This includes “the Board’s expres-
sion of its understanding of the scope of the claim term.”
Id.
    The Board’s view necessarily calls for ranking pheno-
types vis-à-vis each other. That is inherent in the Board’s
construction of “ranked” to mean “ordered.” Final Written
Decision, 2016 WL 7987957, at *4. And the Director
agrees, at least implicitly, when it defends the Board’s
understanding of ranking as supplying a phenotype-to-
phenotype order where a “natural order, or ranking,” does
not exist for the phenotypes. Director’s Br. 1–2.
     But neither the Board’s explanation nor the Director’s
defense of that explanation in this court indicates how the
claim can reasonably be understood to call for that rank-
ing to be based on how similar phenotypes in a database
are to a particular runtime object being scrutinized. The
“broadest reasonable interpretation . . . is an interpreta-
tion that corresponds with what and how the inventor
describes his invention in the specification.” In re Smith
Int’l, Inc., 871 F.3d 1375, 1382–83 (Fed. Cir. 2017); see
Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 1292, 1298
(Fed. Cir. 2015) (prosecution history is relevant to this
inquiry as well), overruled in another respect by Aqua
Prods., Inc. v. Matal, 872 F.3d 1290 (Fed. Cir. 2017); In re
NTP, Inc., 654 F.3d 1279, 1288 (Fed. Cir. 2011) (“While
the Board must give the terms their broadest reasonable
construction, the construction cannot be divorced from the
specification and the record evidence.”); In re Suitco
Surface, Inc., 603 F.3d 1255, 1260 (Fed. Cir. 2010) (“The
broadest-construction rubric . . . does not give the PTO an
unfettered license to interpret claims to embrace anything
remotely related to the claimed invention. Rather, claims
should always be read in light of the specification and
teachings in the underlying patent.”). Here, the Board’s
central understanding is unreasonable in light of the
SOPHOS LIMITED   v. IANCU                                11



specification and, indeed, of the claim’s own statement of
its objective.
    We have been pointed to nothing in the ’218 patent
that discloses ranking the predetermined phenotypes
according to their degree of similarity to a particular set
of malicious behaviors observed in a particular runtime
object. To the contrary, the patent speaks consistently of
seeking a “match” of a phenotype for the runtime object’s
set of malicious-behavior indications, never of examining
degrees of similarity. ’218 patent, Abstract; col. 17, lines
41–48, 64. In addition, the Board’s notion would call for
re-ranking the group of phenotypes with every new
runtime object that is evaluated. The patent says nothing
to that effect.
     More fundamentally, the Board’s notion of ranking
the phenotypes by how similar each is to a particular
runtime object is detached from the essential function of
the invention. As claim 1 itself makes clear, the function
of the comparison of a runtime object to phenotypes is to
develop information about the threat presented by a
runtime object, whose risk of being any type of malware is
not known before the comparison. That risk information
comes from matching behavior indications observed in the
runtime object with a phenotype independently assessed
for its threat indication, i.e., what a particular phenotype
indicates about the presence of a certain kind of malware.
See, e.g., ’218 patent, col. 18, lines 36–41 (one phenotype
may indicate that the collection of observed behavior
indications is “bad” while another may indicate, more
specifically, that the “process is exhibiting the same
behavior as [a known] family of malware”); J.A. 529
(Finjan’s statement to the Board that “[t]he purpose of
ranking the phenotypes is to assess the risk that the
runtime object is malware”). It is the phenotype-to-
phenotype ranking, independent of similarity to the
runtime object, that is the source of the information used
to evaluate the runtime object, and to trigger a content
12                                  SOPHOS LIMITED   v. IANCU



analysis and action based on the evaluation, which is the
claimed invention’s stated function. ’218 patent, col. 1,
lines 43–58; col. 18, lines 26–30. Yet the Board’s notion of
similarity-based ranking eliminates the essential inde-
pendent source of information for assessing the runtime
object, and it leaves nothing in its place that the Board or
the Director has explained would still allow the claimed
invention to perform its function.
     The Board fundamentally misread the patent when it
said, in its crucial paragraph, that “[t]he reason for the
comparison . . . is to identify the most problematic pheno-
type.” Final Written Decision, 2016 WL 7987957, at *5
(emphasis added). That statement gets the direction of
inference in the patented process backwards. The point of
the comparison is not to start with a known danger pre-
sented by the runtime object and infer how problematic a
phenotype is by the degree of similarity to the runtime
object. The danger of the runtime object is not yet known.
The point of the comparison is to infer something about
precisely that danger, by using independent information
(through ranking) about how problematic a particular
matched phenotype is. Ranking of phenotypes inde-
pendently of similarity to the runtime object is an essen-
tial component of that process.
    In short, nothing in the claims, the specification, or
the prosecution history supports the Board’s understand-
ing that the predetermined phenotypes are ranked based
on their similarity to the observed malicious behavior
indications. We conclude that the Board’s understanding
is “divorced from the specification” and is “legally incor-
rect.” Smith, 871 F.3d at 1382 (quoting Microsoft, 789
F.3d at 1298).
   The Board’s incorrect understanding of why and how
ranking is performed in the context of the ’218 patent
appears to be a central basis for its determination that
Lee and Farley disclose the “are ranked” limitation. But
SOPHOS LIMITED   v. IANCU                            13



we do not decide the issue of whether the prior art dis-
closes the “are ranked” limitation under a proper con-
struction.   We remand to the Board for further
proceedings consistent with this opinion.
                            III
   The Board’s decision is vacated and the matter re-
manded for further proceedings.
   No costs.
               VACATED AND REMANDED
