My reading

In the haftarah the prophet speaks to the people: "'My people, remember what Balak king of Moab plotted against you, and how Balaam son of Beor responded to him. [Recall your passage] from Shittim to Gilgal, that you may know the righteous acts of the Lord" (Micah 6:5). This passage refers to two major topics in the parasha: (1) Balak and Balaam and (2) Shittim, which is part of Moab.

Micah preaches against idolatry and turning away from God, but his tone is different from that of other prophets. While the latter warn of God's wrath and severe punishments, Micah offers a more paternal God, one who wishes to make peace with His people:
"O My people, what wrong have I done you? How have I wearied you? Testify against me!" (Micah 6:3). He reminds the Israelites of Balaam, who was invited by Balak king of Moab to curse the people of Israel, but the Lord put words of blessing in his mouth instead. Balak was confused: "Enraged at Balaam, Balak struck his hands together. 'I called you,' Balak said to Balaam, 'to damn my enemies, and instead you have blessed them three times!'" (Num. 24:10). Balaam's reply: "'Balaam replied to Balak, 'But I even told the messengers you sent to me: Though Balak were to give me his house full of silver and gold, I cannot of my own accord to anything, good or bad, that is contrary to the Lord's command. What God says, that I must say.'" (Num. 24:12-13)

As for Shittim: This was the last encampment before entering Canaan. Shittim was in Moab, the very same land where Balaam spoke, and where the Israelites were tempted to take part in the idolatrous worship of Baal of Peor and to lie with Moabite women. Even then God did not abandon them, but carried them across the Jordan to Gilgal, the very first station in the promised land. The people must remember His "righteous acts" and act in accordance with His commandments. For "He has told you…what is good and what is required of you: Only to do justice, to love mercy, and to walk humbly with your God" (Micah 6:8)