Your Browser is not longer supported

Please use Google Chrome, Mozilla Firefox or Microsoft Edge to view the page correctly
Loading...

{{viewport.spaceProperty.prod}}

Example of evaluation

&pagelevel(4)&pagelevel

Examples of the formation of complex condition expressions are given in "ADD-SELECTION-CONDITIONS Define selection conditions".Examples of evaluation in connection with preselection and postselection are provided in "Monitoring special security-relevant activities".

In this example, the SAT file manager would like to achieve the following:

  1. Detect potential attempts at intrusion during the preceding session. To do this it is necessary to select the audit records of rejected LOGON attempts from the SATLOG file.

  2. Create an analysis file containing all events that relate to file objects. This file is to be analyzed decentrally at a later time.

Prerequisites

  • The audit attribute for all switchable user IDs, in other words all except those with the SECURITY-ADMINISTRATION or FILE-MANAGEMENT privilege, has been set to OFF:

    /modify-sat-preselection user-auditing=*all-switchable(*off)

  • The audit attribute of all events for which it is allowed to be changed has been set to OFF in the preselection (see “Individual control of selection). Exception: if the “check user ID” event (UCK) with the result “FAILURE” has been selected for logging:

    /modify-sat-preselection event-auditing=
                             uck(audit-switch=*on(result=*failure))

  • The session to be evaluated was session number 137, beginning on 2018-03-01.

The SAT file manager begins evaluation by starting SATUT:

/ start-satut


The input file that is selected is the SATLOG file from session 137:

//select-input-files input-files=*std(session-number=137)

To obtain an overview of the activities in the selected session, the SAT file manager arranges for statistics to be output to SYSOUT:

//show-statistics output=*sysout

The following output is obtained (the precise meaning of the individual output fields is explained with the statement SHOW-STATISTICS):

Input-files of statement = :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-01.137.01
                           :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-01.137.02
                           :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-02.137.03
Begin of analyzed period : 2018/03/01  10:19:21.24
End   of analyzed period : 2018/03/02  17:44:34.23
Elapsed time             =      113113 s     =     1 d  26713 s
Records/hour             =       53.56
# of records             =        1683
Mean length              =      102.00
Mean kbytes/hour         =        5.54
SUMMARY OF EVENTS
-----------------
     Event-class                         # events  # events/h
     -----------                         --------  ----------
 1 : DMS
       Files                                  711       22.63 
       Security                               733       23.33 
       Rename Files                             5        0.16 
 2 : Catalog Management                         0        0.00 
 3 : Job Enable (Dialog & Batch)
       Success                                 33        1.05 
       Failure                                  6        0.19 
 4 : Job (Rest)                                33        1.05 
 5 : Job Variables                              0        0.00 
 6 : BLS                                       15        0.48 
 7 : Spool
       Jobs                                     0        0.00
       Devices                                  0        0.00 
 8 : PLAM/ILAM                                 20        0.64 
 9 : DSSM
       Connection/Disconnection                 2        0.06 
       Catalog Management                      17        0.54 
10 : Syntax Files                               0        0.00 
11 : Users/Groups/Privileges
       Users                                   87        2.77 
       Privileges                               0        0.00 
       Groups                                   0        0.00 
12 : Object Protection
       GUARDS                                   0        0.00 
       Coowner Protection                       0        0.00 
       Default Protection                       0        0.00 
       Access Control List                      0        0.00 
13 : System Access Control Management
       Terminal Sets                            0        0.00 
       Operator Roles                           0        0.00 
       Keys                                    13        0.41 
14 : SAT                                        2        0.06 
15 : UTM                                        0        0.00 
16 : SESAM                                      0        0.00 
17 : POSIX
       Files and Directories                    0        0.00 
       Child Processes                          0        0.00 
       Processes                                0        0.00 
       System Resources                         0        0.00 
18 : Communication Methods
       DCAM                                     0        0.00 
       BCAM                                     0        0.00 
       IP Security                              0        0.00 
19 : Memory Pools                               0        0.00 
20 : Events
       Serialization                            0        0.00 
       Eventing                                 0        0.00 
21 : Fast Intertask Communication               0        0.00 
22 : Storage Class Events                       0        0.00 
23 : Data Spaces                                0        0.00 
24 : Volume                                     0        0.00 
25 : ADAM device management                     0        0.00 
26 : ANY event (system exit)                    0        0.00 
 #  EVENT  # SUCC   # FAIL   # NONE    LEN SUCC   LEN FAIL   LEN NONE  % EVENTS  % FAIL(EVENT)    RECORDS/HOUR
--- -----  ------   ------   ------    --------   --------   --------  --------  -------------    ------------
  1 FCD        59        0        0      108.61       0.00       0.00      3.51           0.00            1.88
  2 FCL       298        0        0       97.52       0.00       0.00     17.71           0.00            9.48
  3 FCS        58        0        0      106.02       0.00       0.00      3.45           0.00            1.85
  4 FDD        64        2        0      100.62      99.00       0.00      3.92           3.03            2.10
  5 FDS        64       20        0      103.94     100.50       0.00      4.99          23.81            2.67
  6 FED        33        0        0      101.09       0.00       0.00      1.96           0.00            1.05
  7 FMD        92        0        0       95.16       0.00       0.00      5.47           0.00            2.93
  8 FMS        11        0        0      121.91       0.00       0.00      0.65           0.00            0.35
  9 FRD       162        1        0      100.68      97.00       0.00      9.69           0.61            5.19
 10 FRN         5        0        0      148.60       0.00       0.00      0.30           0.00            0.16
 11 FRS       391      189        0      106.45     110.13       0.00     34.46          32.59           18.46
 12 JBE        16        2        0       81.06      71.50       0.00      1.07          11.11            0.57
 13 JDE        17        4        0       79.29      83.75       0.00      1.25          19.05            0.67
 14 JED        16        0        0       58.94       0.00       0.00      0.95           0.00            0.51
 15 JIN        17        0        0       69.00       0.00       0.00      1.01           0.00            0.54
 16 KTC        13        0        0      125.00       0.00       0.00      0.77           0.00            0.41
 17 LCL        10        0        0      128.50       0.00       0.00      0.59           0.00            0.32
 18 LEE        10        0        0      124.50       0.00       0.00      0.59           0.00            0.32
 19 SCR        14        3        0       79.71      78.33       0.00      1.01          17.65            0.54
 20 SDS         2        0        0       85.00       0.00       0.00      0.12           0.00            0.06
 21 UAD         2        0        0       81.00       0.00       0.00      0.12           0.00            0.06
 22 UCK        71       10        0       82.70      82.90       0.00      4.81          12.35            2.58
 23 UML         2        0        0       81.00       0.00       0.00      0.12           0.00            0.06
 24 URM         1        1        0       81.00      81.00       0.00      0.12          50.00            0.06
 25 XLD        10        0        0      199.00       0.00       0.00      0.59           0.00            0.32
 26 XUL         5        0        0       80.00       0.00       0.00      0.30           0.00            0.16
 27 ZBG         3        0        0      245.33       0.00       0.00      0.18           0.00            0.10
 28 ZCH         2        0        0      130.00       0.00       0.00      0.12           0.00            0.06
 29 ZND         3        0        0       83.33       0.00       0.00      0.18           0.00            0.10
--- -----  ------   ------   ------    --------   --------   --------  --------  -------------    ------------
TOTAL:       1451      232        0      101.26     106.65       0.00    100.00          13.78            53.6

The SAT file manager defines the first selection condition with the name “badlog”. This condition relates to all records that concern the “check user ID” event with the result “FAILURE”.

//add-selection-conditions name=badlog, -
// condition=evt equal ’uck’ and res equal f

The second selection condition by the name of “file” relates to records in which events are logged whose short name begins with the letter “F”. These are all events which relate to file objects.

//add-selection-conditions name=file,condition=evt match ’f*’

The following command has the effect that editing for both conditions is executed in one step. All records that satisfy the selection condition “badlog” are written to work file 0, while all records that satisfy the “file” condition are written to work file 5.

//start-selection from-file=*input-files, -
//                  to-file=(*parameters(condition-name=badlog), -
//                           *parameters(file=5,condition-name=file))

%  SAE7001 'START-SELECTION' STATEMENT TERMINATED. '10' RECORDS SELECTED IN WORK FILE  
 ' 0'
%  SAE7001 'START-SELECTION' STATEMENT TERMINATED. '1449' RECORDS SELECTED IN WORK  
 FILE ' 5'


There were therefore 10 unsuccessful LOGON attempts and 1449 events relating to file objects.
The records with the events relating to file objects are written to the ANALYZE.FILE-EVENTS file for the purpose of decentralized analysis.

//save-selected-records to-reduction-name=analyze.file-events,from-file=5

As the SAT file manager considers the number of unsuccessful LOGON attempts to be too high for immediate evaluation, he would like to restrict the selection still further. The first step is to obtain information about the existing selection conditions.

//show-selection-conditions

SELECTION CONDITION NAME : BADLOG
SELECTION CONDITION      : 
                            EVT EQUAL 'UCK' 
                        AND RES EQUAL F 
 ================================================================================
SELECTION CONDITION NAME : FILE
SELECTION CONDITION      : 
                            EVT MATCH 'F*' 
 ================================================================================


The SAT file manager would like to evaluate only failed LOGON attempts made with the “TSOS” user ID. To do that it is necessary to define another selection condition to select records containing the value TSOS in the logged data field OBJ-UID (see “Tables of auditable information on object-related events (1)”).

//add-selection-conditions name=uidtsos,condition=obj-uid equal ’tsos’

The SAT file manager then initiates a second stage of editing. All records from work file 0 that satisfy the “uidtsos” condition are to be written to work file 1. As the records in work file 0 already satisfy the “badlog” condition, the result of this editing is the set of all records for which both conditions (“badlog” and “uidtsos”) are true.

//start-selection from-file=0, -
//                  to-file=*parameters(file=1,condition-name=uidtsos)

%  SAE7001 'START-SELECTION' STATEMENT TERMINATED. '3' RECORDS SELECTED IN WORK FILE  
 ' 1'


Now the result of this selection is only three records. These are to be output to SYSLST for detailed evaluation.

//show-selected-records from-file=1

Finally the SAT file manager outputs a set of statistics for the session, with a histogram, to SYSLST. The evaluation run is then terminated.

//show-statistics from-file=*input-files,histogram=*yes
//end

%  SAE5004 SAT FILE EVALUATOR TERMINATED NORMALLY

SYSLST shows the result of //SHOW-SELECTED-RECORDS on pages 1 and 2.

SATUT                  V05.5A                        2018-03-06 15:44:22                                                PAGE       1
PROCESSED  STATEMENT : SHOW-SELECTED-RECORDS
************************************************************************************************************************************
INPUT-FILES OF STATEMENT :
                           :PCO4:$SYSAUDIT.#SATUT.WORK-01.06.154351
SATUT                  V05.5A                        2018-03-06 15:44:22                                                PAGE       2
PROCESSED  STATEMENT : SHOW-SELECTED-RECORDS
************************************************************************************************************************************
EVT RES DATE     TIME   TSN  USER-ID
UCK  F  20180301 163627 0DHC TSOS     OBJ-UID= TSOS                 STATION= $$$06015             PROCNAM= XYZ0231X
                                      CHKMODE= DIALOG               REJR   = 03400001
UCK  F  20180302 141855 0DHG TSOS     AUDITID= D4C3C8C88995A97CC6E2C34BD5C5E3                     OBJ-UID= TSOS
                                      STATION= $$$06007             PROCNAM= XYZ4711X             CHKMODE= NET-DIALOG-ACCESS
                                      REJR   = 02400001             PRINCCL= MCHHinz@FTS.NET
UCK  F  20180302 144612 0DHI TSOS     AUDITID= D4C3C8D2A495A97CC6E2C34BD5C5E3                     OBJ-UID= TSOS
                                      STATION= $$$06009             PROCNAM= XYZ0815X             CHKMODE= NET-DIALOG-ACCESS
                                      REJR   = 1E400001             PRINCCL= MCHKunz@FTS.NET

The following part of the list shows the result of //SHOW-STATISTICS and is largely identical to the statistics output to SYSOUT at the start of the session. It also contains the histogram of the events.

SATUT                  V05.5A                        2018-03-06 16:17:07                                                PAGE     1
PROCESSED  STATEMENT : SHOW-STATISTICS
**********************************************************************************************************************************
Input-files of statement = :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-01.137.01
                           :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-01.137.02
                           :PCO4:$SYSAUDIT.SYS.SATLOG.2018-03-02.137.03
Begin of analyzed period : 2018/03/01  10:19:21.24
End   of analyzed period : 2018/03/02  17:44:34.23
...
SATUT                  V05.5A                        2018-03-06 16:17:07                                                PAGE     4 
PROCESSED  STATEMENT : SHOW-STATISTICS
***********************************************************************************************************************************
                            # +---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
2018/03/01  10:19           1 |ZZ
2018/03/01  10:20          37 |FFFFFFFFF|FFFFFFFFJ|JJJJJKKSS|SSSSSSSSS|SUUUU
2018/03/01  10:21          35 |FFFFFFFFF|FFFFFFFFF|FFFJJJJJJ|JJJSSSSUU|UU
2018/03/01  10:22           4 |JJKKUUU
2018/03/01  10:23           1 |UU
2018/03/01  10:24           4 |JJKKUUU
2018/03/01  10:25           2 |JJUU
2018/03/01  10:26           3 |JJUUU
2018/03/01  10:27           2 |JJUU
2018/03/01  10:28           0 |
2018/03/01  10:29           0 |
2018/03/01  10:30           0 |
2018/03/01  10:31           3 |FFFUU
2018/03/01  10:32           1 |UU
             ...
2018/03/02  16:48          30 |FFFFFFFFF|FFFFFFFFF|FFFFFFFFF|FFFXX
2018/03/02  17:27           2 |FFF
2018/03/02  17:28          22 |FFFFFFFFF|FFFFFFFFF|LLLLXXX
2018/03/02  17:42           5 |FFFFFJJ
2018/03/02  17:43          19 |FFFFFFFFF|FFFFFFJJJ|SSXX
2018/03/02  17:44           2 |FFZZ
                            # +---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
SATUT                  V05.5A                        2018-03-06 16:17:07                                                PAGE     9 
PROCESSED  STATEMENT : SHOW-STATISTICS
***********************************************************************************************************************************
EXPLANATION ON USED LETTERS:
----------------------------
F : FCD, FCL, FCS, FDD, FDS, FED, FMD, FMS, FRD, FRN, FRS
J : JBE, JDE, JED, JIN
K : KTC
L : LCL, LEE
S : SCR, SDS
U : UAD, UCK, UML, URM
X : XLD, XUL
Z : ZBG, ZCH, ZND

In a final evaluation stage, which can only partly be automated with SAT or by programming, the selected records must be evaluated in order to determine what further action needs to be taken, if at all.

In the example, the two selected records in SYSLST are evaluated manually on the basis of “Tables of auditable information on object-related events (1)”.

EVT RES DATE     TIME   TSN  USER-ID
UCK  F  20180301 163627 0DHC TSOS     OBJ-UID= TSOS                 STATION= $$$06015             PROCNAM= XYZ0231X
                                      CHKMODE= DIALOG               REJR   = 03400001
UCK  F  20180302 141855 0DHG TSOS     AUDITID= D4C3C8C88995A97CC6E2C34BD5C5E3                     OBJ-UID= TSOS
                                      STATION= $$$06007             PROCNAM= XYZ4711X             CHKMODE= NET-DIALOG-ACCESS
                                      REJR   = 02400001             PRINCCL= MCHHinz@FTS.NET
UCK  F  20180302 144612 0DHI TSOS     AUDITID= D4C3C8D2A495A97CC6E2C34BD5C5E3                     OBJ-UID= TSOS
                                      STATION= $$$06009             PROCNAM= XYZ0815X             CHKMODE= NET-DIALOG-ACCESS
                                      REJR   = 1E400001             PRINCCL= MCHKunz@FTS.NET

According to the table for the object USERID on "Tables of auditable information on object-related events (2)", “obj-uid” and “chkmode” are always logged, “station”, “procnam”, “rejr” and “princcl” may be logged.

One possible approach is to examine whether a cluster of logon attempts that were rejected because of user error has occurred at a particular data terminal or in a batch. This could indicate that an attempt has been made to penetrate the system by trying out different passwords.

In this case the analysis shows that only three logon attempts for TSOS (obj-uid) in dialog mode (chkmode) were rejected due to user error (rejr) throughout the entire evaluation period of more than 24 hours (see table on "Tables of auditable information on object-related events (2)"). What is more, these attempts were made from different data terminals (station and procnam). As a consequence, analysis in this case would produce the overall result “harmless”.