The first spam was a bit of a fail as it didn't have the link, the second spam contained a link the the bumerang.cc website.
Date: 19 June 2014 21:40
subject: World Political News
You can see all World Political News at our web site.Just click on link below
From: Customer support
Date: 19 June 2014 13:43
Subject: Your invoice for June 2014
See your invoice for June 2014 by click on link below
The link in the second email goes to the amusingly-named www.bumerang.cc/asdaa/sploit.php - amusing because "sploit" is of course slang for "exploit". Although I have seen exploit kits that contain obvious things like this as a sort of joke, it is also a bit obvious don't you think?
But there is no exploit kit at this "sploit.php" location.. it 404s. But in fact I can see no evidence that there has ever been an exploit in this location, this URLquery report from yesterday (the earliest I can find) also shows a 404. So perhaps the exploit has been deleted? Or perhaps it was never there in the first place..
As I mentioned, there are a pair of emails. The one with the working link looks like a fake invoice malspam, but the other one has the subject "World Political News" and the body "You can see all World Political News at our web site.Just click on link below".
It turns out that bumerang.cc is a news site, covering topics of interest in Moldova in the Romanian, English and Russian languages. Unlike most multilingual news sites, the content is different depending on the language.. and the default Russian language part of the site has a lot of articles on the rather corrupt breakaway region of Transnistria which is strongly pro-Russian and which seems to be getting drawn in to the godawful mess that is the Ukraine crisis.
Transnistria has a reputation for corruption and organised crime, so perhaps bumerang.cc has published something that somebody in Transnistria doesn't like. Joe Jobs against sites dealing in Russian politics are quite common, and the messages do bear several hallmarks of being fakes.
Given that there is no evidence of malware on this site, the fishy nature of the spam and the topic areas of the site itself then I am minded to think that this is a Joe Job and bumerang.cc are not behind this spam run.
UPDATE 1 2014-06-24. Another variant..
From: Bumerang News
Date: 24 June 2014 21:24
Subject: SENSATION NEWS!Ukraine Will Wage War With Russia
Russia's War Against Ukraine! All at our web site. Just click on link below