Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e41a09da2270dbfe…

MALICIOUS

Office (OLE)

193.5 KB Created: 2020-07-05 19:30:39 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 06bfc7f420da76744608c7b8adacbd4e SHA-1: 46152b701acf52a0c1c9f0c8de9f8a73974394a1 SHA-256: e41a09da2270dbfe8bf1e8e7fd0c3f4d3e44228a823beb78a4df34fdcf9b9778
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 macro-enabled document that contains an Auto_Open macro. Heuristics indicate that the macro attempts environment evasion and uses dangerous formula APIs, including a RUN function. The document body also contains a lure to enable macros, suggesting a malicious intent to execute the embedded XLM macro.

Heuristics 5

  • 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.
  • XLM Auto_Open environment-evasion close gate critical OLE_XLM_ENVIRONMENT_EVASION_CLOSE
    Excel 4.0 macro sheet auto-executes environment checks with GET.WORKSPACE / GET.WINDOW, then shows a fake corruption/error message and closes the workbook when the host fails those checks. This is a malware sandbox-evasion pattern, even when the later payload stage is hidden behind obfuscated defined-name flow.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

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) 77507 bytes
SHA-256: bc9a2b103c7ceb496eca8b08679f4e657662846706678103467a013fc7a53be5
Preview script
First 1,000 lines of the extracted script
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  x
' 0085     18 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  SODXOEScL
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     23 LABEL : Cell Value, String Constant - aaZePIPt len=0 
' 0018     21 LABEL : Cell Value, String Constant - alrnyQ len=0 
' 0018     53 LABEL : Cell Value, String Constant - anCjBmqQFCvOLiEcieqtIdfoysWmFZsmcIRRQU len=0 
' 0018     17 LABEL : Cell Value, String Constant - at len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  x!IY50964 
' 0018     20 LABEL : Cell Value, String Constant - besOQ len=0 
' 0018     60 LABEL : Cell Value, String Constant - BGqxFVvuLBEvUxcaIwRIyMWFFssTcoRkQnGSGDwPMjTdj len=0 
' 0018     41 LABEL : Cell Value, String Constant - bkljoMSZERQgjmeDSLvdfzchur len=0 
' 0018     23 LABEL : Cell Value, String Constant - bQkbSfqZ len=0 
' 0018     29 LABEL : Cell Value, String Constant - bQkbSfqZYMxZvI len=0 
' 0018     59 LABEL : Cell Value, String Constant - BRxEXfUzvvtykdkPpbquxpOrWGCqLBrGQyylYzViwevh len=0 
' 0018     30 LABEL : Cell Value, String Constant - bTPbrHcQZwrVXEX len=0 
' 0018     57 LABEL : Cell Value, String Constant - BVxCQNvJiiKSeHaGevWvHBTDZJUaWhyNVWgEybdKQj len=0 
' 0018     26 LABEL : Cell Value, String Constant - BwJaoKxHeZD len=0 
' 0018     21 LABEL : Cell Value, String Constant - bXizPk len=0 
' 0018     25 LABEL : Cell Value, String Constant - CbEjTPDYOF len=0 
' 0018     55 LABEL : Cell Value, String Constant - cmWVJuWsFTBSEIiWUOgdzVuzvILavwGQLoEWqKFt len=0 
' 0018     49 LABEL : Cell Value, String Constant - cMXdZkCDYajHnRhOUnvkQMMKPBtBfGrHLO len=0 
' 0018     20 LABEL : Cell Value, String Constant - cSxHH len=0 
' 0018     39 LABEL : Cell Value, String Constant - cWolIdDIEQTiEFOYTwMfySNC len=0 
' 0018     24 LABEL : Cell Value, String Constant - dBvZbIchp len=0 
' 0018     58 LABEL : Cell Value, String Constant - DfkyudqQQrBNoJnMeEepjCkIrCIEQgvDFOlgKMsySaP len=0 
' 0018     32 LABEL : Cell Value, String Constant - dlaGPQOTqwFivuLPR len=0 
' 0018     43 LABEL : Cell Value, String Constant - dqdQrOMoWnZdEdoiBxVqPIEPguQE len=0 
' 0018     21 LABEL : Cell Value, String Constant - dqpGKM len=0 
' 0018     45 LABEL : Cell Value, String Constant - DUGKkKVPhfCXvokvNbxkuSNqrYsxGv len=0 
' 0018     24 LABEL : Cell Value, String Constant - dXpmJsEJG len=0 
' 0018     22 LABEL : Cell Value, String Constant - EbJlCio len=0 
' 0018     20 LABEL : Cell Value, String Constant - eBZRN len=0 
' 0018     24 LABEL : Cell Value, String Constant - eCjNcJPiq len=0 
' 0018     22 LABEL : Cell Value, String Constant - EdrkVDF len=0 
' 0018     58 LABEL : Cell Value, String Constant - ELNWtoSUBHaiXDyyxCntBSsrIxBsRuZXFtOEuJTCCoo len=0 
' 0018     23 LABEL : Cell Value, String Constant - emnxVQtu len=0 
' 0018     22 LABEL : Cell Value, String Constant - etPQZje len=0 
' 0018     24 LABEL : Cell Value, String Constant - EvgOQkNSf len=0 
' 0018     23 LABEL : Cell Value, String Constant - FEJtmtYy len=0 
' 0018     34 LABEL : Cell Value, String Constant - FfqkDzXsRJGRiwSGPnh len=0 
' 0018     20 LABEL : Cell Value, String Constant - FjhQE len=0 
' 0018     38 LABEL : Cell Value, String Constant - FlGLTJoxxvBYfmRddswzrQf len=0 
' 0018     36 LABEL : Cell Value, String Constant - fLiBaBMGYIeOYeamESabk len=0 
' 0018     20 LABEL : Cell Value, String Constant - fLUUS
... (truncated)