CVE-2018-4878 (Flash Player up to and Exploit Kits

2018-03-09 - Exploit Integration

CVE-2018-4878 (Flash Player up to and Exploit Kits

The CVE-2018-4878 is a bug that allows remote code execution in Flash Player up to, spotted in the wild as a 0day, announced by the South-Korean CERT on the 31st of January. Patched on February 6, 2018 with ASPB18-03. Seen in malspam campaign two weeks after, it’s now beeing integrated in Exploit Kits.

This is, as far as i know, the first new working RCE integrated in non targeted Exploit Kit1 since CVE-2016-0189 in july 2016 (!).


GreenFlash Sundown:

Spotted on the 2018-03-09 (but probably there since several days)

CVE-2018-4878-Successful pass on GreenFlash Sundown

Figure 1: Greenflash Sundown successfully deploying Hermes 2.1 Ransomware after exploiting Flash in IE11 on Windows 7 - 2018-03-09

GreenFlash is a private heavily modified version of Sundown EK spotted in october 2016 by Trendmicro. It’s beeing exclusively used by the “WordsJS” (aka “ShadowGate”) group. This group is getting traffic from crompromised OpenRevive/OpenX advertising server since at least may 2015.


Figure 2: Some tagged activity from WordsJS displayed in MISP.

Some references about the activities of this group:

Blog/Tweet Date Author
OpenX Hacks example (malvertising) 2015-05-19 @malekal_morte
[Tweet] Malvertising via psychecentral[.]com 2015-10-12 @BelchSpeak […] Angler EK: Installs bedep, vawtrak and POS malware 2015-11-02 Cyphort
Music-themed Malvertising Lead To Angler 2016-01-19 Zscaler
[FR] Exemple d’une Malvertising sur OpenX 2016-04-13 @malekal_morte
Top Chilean News Website Emol Pushes Angler Exploit Kit 2016-05-11 Malwarebytes
Is it the End of Angler ? 2016-06-11 MDNC Shadowed Domains Lead to Neutrino EK 2016-08-12 RiskIQ
Talos ShadowGate Take Down: Global Malvertising Campaign Thwarted2 2016-09-01 Talos
Sundown EK from sends Locky Ransomware 2016-10-17 @malware_traffic
New Bizarro Sundown Exploit Kit Spreads Locky 2016-11-04 Trendmicro

Files: Fiddler on VT - Pcap on VT (note: some https proxies were used)

IOC Type Comment Date
bannerssale[.]com|159.65.131[.]94 domain|IP Sundown GF Step 1 2018-01-09
aquaadvertisement[.]com|159.65.131[.]95 domain|IP Sundown GF Step 2 2018-03-09
listening.secondadvertisements[.]com|207.148.104[.]5 domain|IP Sundown GF Step 3 2018-03-09
65bd3d860aaf8874ab76a1ecc852a570 md5 Ransomware Hermes 2.1 2018-03-09
f84435880c4477d3a552fb5e95f141e1 md5 Ransomware Hermes 2.1 2018-03-10

If you saw this kind of traffic in your perimeter/telemetry, i’d be happy to get more referer


  • 2018-03-10 - 15:40 GMT - Removed mention of steganography. @smogoreli: “simple offset in the dat file”


  • Thanks to Genwei Jiang (FireEye) for the CVE identification.
  • Thanks to Joseph Chen for inputs allowing the capture of a fresh pass of GreenFlash Sundown.
  • Thanks to @GelosSnake & @baberpervez2 for the ping on suspicious activity that could be associated to “WordsJS” (aka “ShadowGate”) and triggered those checks.


Spotted on the 2018-04-01


Figure 3: Magnitude successfully deploying Magniber Ransomware after exploiting CVE-2018-4878 on Flash in IE11 on Windows 7 - 2018-04-01

Magnitude is using the WSH injection described by Matt Nelson in August 2017.


Figure 4: UAC prompt on the wsh injection executed upon successful exploitation

Payload is the Magniber Ransomware, first spotted in the wild in october 2017, in a context documented by Trendmicro.


Figure 5: Some tagged activity from Magnigate displayed in MISP.

Select OSINT about this infection chain:

Blog/Tweet Date Author
Magnitude Actor Adds a Social Engineering Scheme for Windows 10 2017-08-03 Proofpoint
[Tweet] Ransomware spread by Magnitude. Hosted behind same infra. KOR focused for now 2017-10-16 Kafeine
Magnitude Exploit Kit Now Targeting South Korea With Magniber Ransomware 2017-10-18 Trendmicro

Files: Fiddler on VT - Pcap on VT (note: some https proxies were used)
IOCs: MISP Json (note: all those are changing almost hourly)

IOC Type Comment Date
finansee[.]credit|209.95.60[.]115 domain|IP Magnigate Step 1 2018-04-01
adex7s92616.fryrids[.]com|144.217.197[.]9 domain|IP Magnigate Step 2 2018-04-01
353kb544cv.anlogs[.]space|66.70.223[.]111 domain|IP Magnitude Exploit Kit 2018-04-01
*.fitpint[.]website|139.60.161[.]43 domain|IP Magniber Payment server 2018-04-01
*.riskjoy[.]pw|162.213.25[.]235 domain|IP Magniber Payment server 2018-04-01
*.ratesor[.]site|198.56.183[.]147 domain|IP Magniber Payment server 2018-04-01
*.accorda[.]space|107.167.77[.]100 domain|IP Magniber Payment server 2018-04-01
*.uxijz4kdhr4jp3wf[.]onion domain Magniber Payment server on tor 2018-04-01
1d4b9c4b4058bfc2238e92c0eebb5906 md5 Magniber Ransomware 2018-04-01


Spotted on the 2018-04-09

Replying to a customer complaining yesterday (2018-04-08) about the lack of CVE-2018-4878, “TakeThat” wrote early this morning (2018-04-09):

Чистки выполняются вовремя
Конечно мы добавили флеш CVE-2018-4878 он доступен на подписке от недели

Translated by google as:

Cleaning is done on time
Of course, we added the flash CVE-2018-4878 it is available on subscription from the week

And indeed today as spotted by @nao_sec:


Figure 6: RIG successfully exploiting CVE-2018-4878 on Flash in IE11 on Windows 7 - 2018-04-09

IOC Type Comment Date
cash111[.]club|18.220.221[.]2 domain|IP Keitaro TDS 2018-04-09 IP RIG 2018-04-09
omega.level7[.]gdn|89.45.67[.]198 domain|IP Urausy C2 2018-04-09
1bd20aa0433f3f03001b7f3e6f1fb110 md5 RIG Flash Exploit 2018-04-09
712385a6073303a20163e4c9fb079117 md5 Urausy - probably as a loader 2018-04-09


Spotted on 2018-06-28, most probably there since 2018-06-16

Despite seeing code pointing to it, we did not saw it properly called in traffic.

Fallout_CVE-2018-4878 Call

Figure 6: Fallout call for CVE-2018-4878 in it's landing 2018-08-30

Blog/Tweet Date Author
Hello “Fallout Exploit Kit” 2018-09-01 Nao_Sec
IOC Type Comment Date
md5 747c32e55b4e847c3274503290507aa1 Fallout Flash Exploit 2018-08-31


  • 2018-04-10 - 10:05 GMT - Modified to reflect payload id: Urausy. Not seen since 2015-06-09


  • Thanks to Kimberly for the payload identification.
  1. For instance CVE-2016-7855 has been integrated as a 0day in Sednit EK in october 2016. 

  2. It was not exactly a malvertising but some ad server compromission and nothing, but a bunch of shadowed domains, was really taken down