Spammers hide from antivirus vendors

We are seeing a lot of SpamTools now. These programs are installed on victim machines secretly, where they proceed to harvest email addresses. The harvested addresses are sent to the SpamTool’s master and used for mass mailings. In most cases, such spammer utilties are then de-installed automatically.

In the beginning, SpamTools harvested all email addresses on the infected machine. Today, we are seeing more and more SpamTools, which are picking and choosing: they fignore addresses containg substrings that point to antivirus and antispam vendors.

The result? When antivirus and anti-spam vendors do not receive mass mailings directly, it takes longer for the security community to react. Spammers get an additional window of opportunity to reach more people.

By the way, many virus writers have used this tactic when writing email worms, which also often do not send infected emails to antivirus vendors in an attempt to stay undetected just a bit longer.

Spammers hide from antivirus vendors

Your email address will not be published. Required fields are marked *



The leap of a Cycldek-related threat actor

The investigation described in this article started with one such file which caught our attention due to the various improvements it brought to this well-known infection vector.

Lazarus targets defense industry with ThreatNeedle

In mid-2020, we realized that Lazarus was launching attacks on the defense industry using the ThreatNeedle cluster, an advanced malware cluster of Manuscrypt (a.k.a. NukeSped). While investigating this activity, we were able to observe the complete life cycle of an attack, uncovering more technical details and links to the group’s other campaigns.

Sunburst backdoor – code overlaps with Kazuar

While looking at the Sunburst backdoor, we discovered several features that overlap with a previously identified backdoor known as Kazuar. Our observations shows that Kazuar was used together with Turla tools during multiple breaches in past years.

Subscribe to our weekly e-mails

The hottest research right in your inbox