Section 9. The attorney general may bring a civil action in the name of the commonwealth to prevent and restrain violations of section four, five or six of this chapter; as parens patriae on behalf of natural persons residing in the commonwealth, to secure monetary relief for damages sustained by such natural persons to their property by reason of any violation of section four; and on behalf of the commonwealth and its public agencies and political subdivisions for damages sustained, together with costs of suit, for injuries to their property by reason of violations of section four, five or six; provided, however, that unless the attorney general has brought a criminal complaint pursuant to section ten, the attorney general may bring a civil action in the name of the commonwealth to recover a civil penalty of not more than twenty-five thousand dollars for any course of conduct, pattern of activity or activities which violate section four, five or six. In any action brought on behalf of the commonwealth and its public agencies and political subdivisions for damages sustained to their property, if the court finds that the violation was engaged in with malicious intent to injure the commonwealth, public agency or political subdivision, the court may award up to three times the amount of actual damages sustained together with the costs of suit, including reasonable attorneys fees.

In any parens patriae action brought under this section where there has been a judicial determination that a defendant agreed to fix prices in violation of section four of this chapter, damages may be proved and assessed in the aggregate by statistical or sampling methods or by such other reasonable system of estimating aggregate damages as the court permits; a final judgment shall be res judicata as to any claim by any person on whose behalf such action was brought; and any monetary recovery shall be distributed in such manner as the court in its discretion may authorize or may be deemed by the court to be a civil penalty.

The superior court shall have jurisdiction of actions brought under this section. Such actions may be brought in any county where a defendant resides or has his principal place of business or in which the violation occurred in whole or in part, or with the consent of a defendant, the superior court for Suffolk county.

The attorney general may conclude any civil action brought under this section, or any investigation commenced or contemplated under section eight, by the acceptance of a written assurance of discontinuance or consent decree. Any consent decree shall be filed with the superior court and shall constitute a final judgment.