> JapanHacked_
[Resolved][Severity: Major][Phishing][Credential abuse]

Mouse Computer: a phished staff mailbox sent fake emails to 1,220 business customers and partners

One employee gave away a mail ID and password on a fake site, and the account was then used to send phishing emails to business customers and partners.

Disclosed

2020-05-13

Organizations involved

1

Leaked or at risk

Unknown

Downtime

Unknown

What happened

  1. A phishing email reached an employee in purchasing, who gave away a mail ID and password on a fake site. [3]

  2. The account, entered with the stolen password, sent similar phishing emails. Recipients reported them. [2] [3]

  3. Public disclosure. [1]

  4. A second report gave the sequence of events and the number of emails sent. [3]

Impact

1,220 phishing emails went to business customers and partners, and their email addresses may have leaked. [2] [3]

Response

The account password was changed to shut out the intruder, and recipients were told what had happened and asked to delete the email and not enter any ID or password. [2] [3]

Timeline

  1. Started 2020-05-08
  2. Detected 2020-05-12
  3. Disclosed 2020-05-13
  4. 5 days

Attack or cause

Method
[Phishing][Credential abuse]
Impact
[Data leak]
Entry point
Stolen credentials

Data exposed or at risk

[E-mail address]

Organizations involved

Open in organization search

Sources

  1. [1][News]標的型攻撃メールで顧客と取引先のメールアドレス流出(マウスコンピューター)ScanNetSecurity · 2020-05-15 08:00
  2. [2][News]アカウントが乗っ取り被害、フィッシング踏み台に - マウスコンピューターSecurity NEXT · 2020-05-15
  3. [3][News]端緒は購買部社員へのフィッシングメール、標的型攻撃メールによるアカウント情報盗取 第2報(マウスコンピューター)ScanNetSecurity · 2020-05-20 08:00