Based in Ukraine, it is a widespread criminal organization with a reach extending to the United States. Isaak Sirko was a powerful leader.
The Koshka Brotherhood specializes in human and heroin trafficking under cover of the strip clubs they own. Their main rivals in Miami are the Colombian drug cartels with whom they battle for control of the drug trade.
- Murder - Viktor Baskov killed a stripper named Kaja Soroka and then killed Det. Mike Anderson when he discovered her body.
- Drug Trafficking - The Brotherhood buy and sell heroin. They are seen completing a large transaction at The Fox Hole with Det. Joey Quinn standing guard.
- Human Trafficking - The Brotherhood keep the passports of immigrant women and work them through their chain of strip clubs.
- Murder - Isaak Sirko killed Tony Rush, Louis Greene, Andres Rodriguez and two Colombians in his quest to find Viktor Baskov and his killer.
- Murder - Isaak Sirko, George Novikov and Jurg Yeliashkevych forced Alex Dubrozny to commit suicide after he wrote a false confession implying that he murdered Mike Anderson, Kaja Soroka, and Viktor Baskov.
- Murder - George Novikov shot Isaak Sirko fatally in the gut after three assassins failed to kill Isaak.
- Bribery, Extortion, and Evidence Tampering - George Novikov coerced Det. Joey Quinn through money and Nadia to steal the blood evidence implicating Isaak in the triple murder.
- Money Laundering - Miami Metro Vice believed that the strip clubs were used to launder money, but could never prove it.
- Isaak Sirko - High-ranking leader of the organization and a Main Antagonist in Season Seven, he arrived in Miami following the death of one of his associates (Viktor Baskov).
- Viktor Baskov - The mobster who murdered Detective Mike Anderson, he was Dexter's first victim in Season Seven. He was sent to run the Koshka's business operations in Miami, after George Novikov couldn't stop the Columbians from interfering in their drug trafficking.
- Unnamed Hitman - Hired by George Novikov to kill Isaak Sirko
- Benjamin Caffrey - Approved by the Brotherhood to kill Isaak Sirko
- Oleg Mickic - Approved by the Brotherhood to kill Isaak Sirko
- Dexter Morgan - Coerced by Isaak Sirko to kill Oleg Mickic and Benjamin Caffrey
- Detective Joey Quinn - A formerly dirty cop that was pressured to again be on the Koshkas' payroll
- Kaja Soroka - Killed byViktor Baskov
- Mike Anderson - Killed by Viktor Baskov
- Viktor Baskov - Killed by Dexter Morgan
- Tony Rush - Killed by Isaak Sirko
- Louis Greene - Killed by Isaak Sirko
- Andres Rodriguez - Columbian killed by Isaak Sirko
- Biggest Columbian - Killed by Isaak Sirko
- Bartender (Mateo's Bar) - Killed by Isaak Sirko
- Alex Dubrozny - Indirectly; coerced to commit suicide by Isaak, George, and Jurg
- Unnamed Hitman - Killed by Dexter Morgan
- Oleg Mickic - Killed by Dexter Morgan
- Jurg Yeliashkevych - Killed by Hannah McKay
- Benjamin Caffrey - Killed by Isaak Sirko
- Isaak Sirko - Killed by George Novikov
- George Novikov - Killed by Joey Quinn
- Кошка (Koshka) is the Russian word for cat, specifically, female cat. The correct spelling of the word "cat" in Ukrainian - "Кішка" (Kishka)..(Bratva, "Koshka" means "female cat").
- They are the largest scale of Main Antagonists in the series.
- They are the first organized crime syndicate to play a role in Dexter's storyline. (Before that, a drug cartel in Season One played a role in James Doakes' storyline).