Cyltr – see you later – Page 2

Anti-ransomware script solution

Post author By admin
Post date June 17, 2020
No Comments on Anti-ransomware script solution

The idea behind this is simple- if we find out files are being changed quickly, we can still make steps to save much of valuable data from ransomware infection.

That’s why we create a “honeypot” with files likely to be encrypted by ransomware. On windows those have following extensions: doc, docx, jpg, png, xls, xlsx and txt. These files are made with a random content and placed to easily reachable places (meaning not buried deeply in directory structure). Also a ransomware usually goes through the file system structure in alphabetical order, so c:\afile\ would be likely to hit sooner than c:\wrong\dang\files\honeypot\something.

Anyway, now we have the honeypot files, we need to watch over them and as soon as they are changed send alert, disconnect network to prevent further infection or shutdown the computer.

We can solve this completely within a windows batch file with windows utilities involved (certutil.exe for generating md5 hashes and fc.exe for comparing them). A simple task in windows task scheduler runs the .bat in short intervals making the job done.

If you are interested, I am willing to explain more or even sell the code along with documentation.

I have also such application written in C# which runs in background- so no need to use task scheduler- so the emergency action happens immediately when files are enrypted.

Dynamics NAV / Navision

Dynamics NAV- fieldref

In case we need to import field programatically, without direct referencnig, there is a FieldRef in Navision.


setField(tabName : Text[30];fieldId : Integer;mVal : Text[1024])
IF fieldId < 1 THEN EXIT;
IF tabName = 'sometablename' THEN BEGIN
 greRecRef.GETTABLE(greNS); // get table reference
 greFieldRef:=greRecRef.FIELD(fieldId);
 IF FORMAT(greFieldRef.TYPE) = 'Boolean' THEN BEGIN
   IF (mVal = '1') OR (UPPERCASE(mVal) = 'YES') THEN greFieldRef.VALUE:=TRUE
   ELSE greFieldRef.VALUE:=FALSE;
 END ELSE IF (FORMAT(greFieldRef.TYPE) = 'Integer') OR (FORMAT(greFieldRef.TYPE) = 'Decimal') THEN BEGIN
   EVALUATE(mNum,mVal);
   greFieldRef.VALUE:=mNum;
 END ELSE IF (FORMAT(greFieldRef.TYPE) = 'Code') OR (FORMAT(greFieldRef.TYPE) = 'Text') THEN BEGIN
   greFieldRef.VALUE:=mVal;
 END ELSE IF (FORMAT(greFieldRef.TYPE) = 'Date') THEN BEGIN
   EVALUATE(mDate,mVal);
   greFieldRef.VALUE:=mDate;
 END ELSE IF (FORMAT(greFieldRef.TYPE) = 'Time') THEN BEGIN
   EVALUATE(mTime,mVal);
   greFieldRef.VALUE:=mTime;
 END ELSE ERROR('This field type is not yet covered.');
END;

Dynamics NAV / Navision

Dynamics NAV – writing logs

Post author By admin
Post date June 10, 2020
No Comments on Dynamics NAV – writing logs

Something we need in every serious code object- writing logs to a logfile.

{
1)  open log file
}
OpenLogFile()

ltePath:=getMainPath('')+'csvlog.txt';

LogFile.TEXTMODE := TRUE;
LogFile.WRITEMODE(TRUE);
IF NOT LogFile.OPEN(ltePath) THEN
    IF NOT LogFile.CREATE(ltePath) THEN BEGIN
        EXIT; 
    END;
LogFile.SEEK(LogFile.LEN);

{
2) write text line
WriteLog(mess : Text[1000])
LogFile.WRITE(mess);
}

{
3) don't forget to close the file at the end
}
CloseLogFile()
LogFile.CLOSE();

Dynamics NAV / Navision

Dynamics NAV – Importing CSV files

Post author By admin
Post date June 9, 2020
No Comments on Dynamics NAV – Importing CSV files

I learned quite a lot during my 15 years working with Navision. I am going to share some of my precious knowledge here.

I’ll show how can we import a csv file into any NAV table, without any libraries or custom code units.

Importing CSV

Obvious part, which most of my code objects starts with:


Integer - OnPreDataItem()
Integer.SETRANGE(Number,1,1);


readCSV()
mFilePath := getMainPath('downloaded')+'RA_Hertz-DE.csv';

//invalid->ready

//downloaded->ready
lreFileRec.SETRANGE(Path, getMainPath(''));
lreFileRec.SETRANGE("Is a file", TRUE);
lreFileRec.SETFILTER(Name, '*.csv');
IF lreFileRec.FIND('-') THEN REPEAT
 lreNewCSVfile.TEXTMODE := FALSE;
 lreNewCSVfile.WRITEMODE(TRUE);
 IF NOT lreNewCSVfile.OPEN(getMainPath('ready') + '\' + lreFileRec.Name) THEN
     IF NOT lreNewCSVfile.CREATE(getMainPath('ready') + '\' + lreFileRec.Name) THEN
         ERROR('nejde vytvorit soubor');

 lreCSVfile.TEXTMODE := FALSE;
 lreCSVfile.OPEN(lreFileRec.Path + '\' + lreFileRec.Name);
 lreCSVfile.SEEK(0);
 REPEAT
  lreCSVfile.READ(mChar);
  IF mChar='"' THEN mChar := 0;
  IF mChar <> 0 THEN lreNewCSVfile.WRITE(mChar);
 UNTIL lreCSVfile.POS >= (lreCSVfile.LEN);
 lreCSVfile.CLOSE();
 lreNewCSVfile.CLOSE();
UNTIL (lreFileRec.NEXT() =0);

cacheCols();
cacheFields();

//import ready
lreFileRec.SETRANGE(Path, getMainPath('ready'));
lreFileRec.SETRANGE("Is a file", TRUE);
lreFileRec.SETFILTER(Name, '*.csv');
IF lreFileRec.FIND('-') THEN REPEAT
 x:=1;
 mImportFile.OPEN(lreFileRec.Path + '\' + lreFileRec.Name);
 mImportFile.CREATEINSTREAM(mImportStream);
 WHILE NOT mImportStream.EOS DO BEGIN
  mImportStream.READ(mChar);
  //nova radka
  IF mChar=13 THEN BEGIN
   processCSV(x);
   linCnt += 1;
   x:=1;
   CLEAR(gteVals);
  END;
  IF mChar=',' THEN x+=1;
  IF (mChar<>10) AND (mChar<>13) AND (mChar<>',') THEN BEGIN
   gteVals[x]:=gteVals[x] + FORMAT(mChar);
  END;
 END;
 mImportFile.CLOSE;
UNTIL lreFileRec.NEXT()=0;

//ready->imported
//ready->backup

{
 processing a CSV record. gteNAVfield/getNAVtab are arrays telling 1) which CSV fields we want to import and 2) to which fields/tables in NAV
}
processCSV(cnt : Integer)
greNS.INSERT(); // create new record

FOR n:=1 TO cnt DO BEGIN
 //find column name
 IF (gteNAVfield[n] <> '') AND (gteNAVfield[n] <> '?') THEN BEGIN
  lteColName:=gteNAVfield[n];
  lteTabName:=gteNAVtab[n];
  linFieldID:=getFieldID(lteTabName,lteColName);
  setField(lteTabName,linFieldID,gteVals[n]);
 END;
END;

greRecRef.SETTABLE(greNS); //save rec ref into the table
greNS.MODIFY();

{
 gets field id of a table by a field name
 gteNSfieldName is cached array of field names
 ginNSfieldID is cached array of field ids
}
getFieldID(tabName : Text[300];colName : Text[300]) fieldId : Integer
IF tabName = 'Some Table' THEN BEGIN
 FOR n:=1 TO ginRecFieldsCnt DO BEGIN
  IF gteNSfieldName[n] = colName THEN BEGIN
   fieldId:=ginNSfieldID[n]; //field id of NAV table
   EXIT;
  END;
 END;
END;

{
 greRecRef is variable of type RecordRef we point to greNS which is variable of type Record of chosen record
 greFieldRef is variable of type FieldRef which we use to reference to this record fields
}
//sets a field of a table with a value
setField(tabName : Text[30];fieldId : Integer;mVal : Text[1024])
IF fieldId < 1 THEN EXIT;
IF tabName = 'Some Table' THEN BEGIN
 greRecRef.GETTABLE(greNS); // get table reference
 greFieldRef:=greRecRef.FIELD(fieldId);
 greFieldRef.VALUE:=mVal;
END;
{
 after all fields are set, we call settable and modify to save loaded fields into Navision record
 greRecRef.SETTABLE(greNS); //save rec ref into the table
 greNS.MODIFY();
}

for more details about FieldRef and extensions for other FieldTypes, refer to https://cyltr.com/dynamics-nav-fieldref/