Introduction to cyber security – Week 3, Malware

Viruses Inserts copies of itself onto crucial parts of hard disk in applications and data. They are self-replicating and either start when the infected application starts each time or after starting once copy themselves and start each time the computer starts. Mainly written to harm users by destroying data, creating Continue Reading

Introduction to cyber security – Week 2, Authentiation

Passwords – what are they for? Identification and authentication – Systems need to uniquely identify each user and prevent impersonation. Risks and solutions Password sent in plain text Passwords sent over SSL are encypted. Password stored in plain text Hashed version of the password stored in database. Hashing is a Continue Reading

Introduction to cyber security – Week 1, Threat Landscape

Terminology CIA – guiding principal Confidential – only to be read by right people Integrity – only changed by authorised people/processes Availability – available to read/use whenever we want Information assets Information asset could be customer data amongst other things Authentication – necessary to verify identity of source of request Continue Reading

ORA-25017: cannot reference NEW ROWID for movable rows in before triggers

Introduction A couple of triggers were throwing the following error which was strange as in other databases the same code works fine. The problematic database is based on an anonymised customer database and was not a copy of a working internal DB. Error: ORA-25017 Description: cannot reference NEW ROWID for Continue Reading

ORA-00333: redo log read error block XXXX count XXXX

ORA-00333: redo log read error block XXXX count XXXX I encountered this Oracle error when connecting to my database after my laptop lost power and subsequently had some severe Blue Screen issues. According to Oracle, ORA-00333 is caused by an IO error while reading the log described in the accompanying error. The resolution Continue Reading

Excluding WMI system properties with Powershell

When using Windows Management Instrumentation (WMI)  in your Powershell script you will see a load of system properties returned. These are indicated by a preceding “__” (double underscore) as seen below when issuing get-wmiobject -class “Win32_Processor”:   An obvious attempt to prevent these system properties from being returned would be Continue Reading

SQL Server Central Management Server (CMS) Intro

Introduction Central Management Server (CMS) was first introduced in SQL Server 2008, it enables simplified management of multiple MS SQL database servers and instances. My screenshots are taken from SQL Server 2012 but should be relevant in SQL 2008 and 2008 R2 as well. If you are managing more than Continue Reading

ORA-00257: archiver error. Connect internal only, until freed.

When connecting to a database via SQL*Plus (similar error would be displayed via other products) the following error is thrown: SQL*Plus: Release 10.2.0.3.0 – Production on Fri Nov 16 10:15:15 2012 Copyright (c) 1982, 2006, Oracle. All Rights Reserved. ERROR: ORA-00257: archiver error. Connect internal only, until freed. Cause: The Continue Reading