Cassidy announced on Monday he raised nearly $700,000 from July through the end of September, and has more than $3.4 million cash on hand.

Landrieu now has $5.78 million cash on hand.

In a statement announcing her fundraising numbers, Landrieu said her campaign would offer a choice between her record working for Louisiana or "leadership by manufactured crises that wreak havoc on our economy and the American people," a jab at Cassidy and the continued shutdown in Washington.

Her campaign noted that she's fundraising at a faster clip than her 2008 race. She has almost $2.5 million more cash in the bank than she did at the same point during that cycle, and had raised only $830,000 in the same quarter last time she ran for reelection.

The National Republican Senatorial Committee has kept pressure on Landrieu over the past few months based on reports that her husband has taken high-powered Washington lobbyists with business before Landrieu as real estate clients.

In a new attack, the NRSC asks five questions of Landrieu, including how much her family profited from her husband Frank Snellings' work with lobbyists like Tony Podesta.

The attack riffs off a comment Landrieu made on the need to end the shutdown, where she charged: "The Tea Party has to understand that they cannot hold government and our private partners — which are many from big companies like Boeing and Lockheed, to small companies that are represented here — hostage over their inability to get a law that they don't like amended."

Lockheed and Boeing are both clients of Podesta, for whom Snellings has previously acted as realtor.

Landrieu's office has repeatedly said there's nothing inappropriate about the business ties, as has an independent government watchdog group. The senator and her husband have consulted the Senate Ethics Committee to ensure they're following all rules and regulations.

--This piece was updated at 9:12 a.m.