The vast majority of insider IT sabotage is carried out by employees - or ex-employees - who have already showed signs of concerning behaviour such as tardiness, truancy, arguing with colleagues, and poor job performance, according to US researchers.
According to the research - which ought to worry anyone who has difficulty getting into the office on time - 80 per cent of the insider attacks studied were carried out by people who were already known to be disgruntled, but were poorly or ineffectively dealt with by their managers or employers.
The findings come from a five-year insider threat study by researchers from Carnegie-Mellon University's CERT Coordination Centre and the US Secret Service, and recently published as updated advice for the wary.
The study looked at 49 cases where IT systems had been damaged by a disgruntled current or former staffer. The costs of these attacks, which ranged from logic bombs to financial fraud, allegedly ranged from $500 to tens of millions of dollars.
According to the CERT team, 92 per cent of insider attacks followed "a negative work-related event", such as a dispute, demotion or transfer, or being fired - 59 per cent of the saboteurs had already been sacked, and either got into their former employer's systems remotely, using passwords that hadn't been deleted, or had already used their privileged system access to set up the attack before they were thrown out.
The report's authors noted that "86 per cent of the insiders held technical positions. 90 per cent of them were granted system administrator or privileged system access when hired by the organisation".
They said that the most important things organisations must do to protect themselves are to thoroughly terminate system access when an employee leaves, carry out account audits to see who has access to what, and watch out for unhappy staff - perhaps increasing the monitoring of an employee's online activity if they seem disgruntled following one of those negative work-related events (and who wouldn't be?).
However, they add that managers are also likely to be at fault if an insider attack occurs, citing factors such as access management practices that degrade over time due to competing priorities, tension between staff and management, and ineffective management responses to problem behaviour. ®