Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8a941fa7e38fb0…

MALICIOUS

PDF

84.2 KB Created: 2021-06-27 03:53:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: de419b812351da68acb86137cc418c98 SHA-1: a59d26d9cce304c0f832ef27c6e446e9dba8f6e2 SHA-256: 5c8a941fa7e38fb07efd8fa3088252a782e0ca0ac19b3af04a201e9575d0f288
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document contains an embedded JavaScript payload that appears to be designed to download and execute a second-stage payload. The script's description mentions 'Powershell tail file', suggesting an intent to interact with system logs or execute commands. The document also contains numerous links to external sites, many hosted on compromised WordPress installations, which likely serve as distribution points for the malicious payload. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 8

  • Embedded script payload in PDF stream high PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain script execution markers such as ActiveXObject/CreateObject, WScript.Shell, PowerShell, or shell-exec primitives. This is stronger than ordinary PDF JavaScript because it indicates a staged external script payload hidden in stream bytes.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Suspicious extracted artifact medium 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://chcial.ru/uplcv?utm_term=powershell+tail+file PDF link annotation
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/8qcootvkpeb3vh32rrbjc8049a/66368277455.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090b2341b0ba---vawosogizabazomipapo.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/27141958211.pdfIn PDF document text
    • https://noddy.nu/images/file/seresavo.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160855abee7dec---49238573003.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16089d45a37450---wekiz.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c54f95ca48b---82086040976.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160827b84497a5---79422386673.pdfIn PDF document text
    • http://sbsinternationalschool.org/sbsisnew/userfiles/file/kisijebivefane.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7aea8044e---jubeluraxevubob.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c2eb911a14d---setedu.pdfIn PDF document text
    • http://kengosushionlineorder.com/uploads/files/40048002505.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082df26ad431---1450695604.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/9881mhkneromfdtumofjjhoa04/44575100177.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160716d407d4e2---51823203051.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608de4c42a48d---51674240716.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/jomow.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/95124174660.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8b85779d2---tinadu.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608280c48a651---30594603564.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983498a51e4---75720238233.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/buvarufokarapiw.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b24ea5cb18---69490643340.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce49854903---gidefajivapovipef.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/fb5aae05d6786cc9177f1c48b9954a39/23278144065.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plIn macro / runtime command snippet
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_pdf_script_00014b71.bin pdf-embedded-script PDF raw stream script payload at offset 0x14B71 1562 bytes
SHA-256: 9209881b8e2d03cb7237e8b71402dfaab609a527facf2f231e97d096fe9a32ec
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 shell/COM execution token(s).
Preview script
First 1,000 lines of the extracted script
<?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?>
<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Pdftk'>
<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'>

 <rdf:Description rdf:about=''
  xmlns:dc='http://purl.org/dc/elements/1.1/'
  dc:format='application/pdf'>
  <dc:creator>
   <rdf:Seq>
    <rdf:li>Sunehufewo Semuxavu</rdf:li>
   </rdf:Seq>
  </dc:creator>
  <dc:description>
   <rdf:Alt>
    <rdf:li xml:lang='x-default'>Powershell tail file.      ¿A quién le gusta leer logs casi ‘infinitos’? Creo que es una tarea que en Windows por mucho ti</rdf:li>
   </rdf:Alt>
  </dc:description>
  <dc:subject>
   <rdf:Bag>
    <rdf:li>Powershell tail file.      ¿A quién le gusta leer logs casi ‘infinitos’? Creo que es una tarea que en Windows por mucho ti</rdf:li>
   </rdf:Bag>
  </dc:subject>
  <dc:title>
   <rdf:Alt>
    <rdf:li xml:lang='x-default'>Powershell tail file</rdf:li>
   </rdf:Alt>
  </dc:title>
 </rdf:Description>

 <rdf:Description rdf:about=''
  xmlns:pdf='http://ns.adobe.com/pdf/1.3/'
  pdf:Producer='Pdftk'/>

 <rdf:Description rdf:about=''
  xmlns:xmp='http://ns.adobe.com/xap/1.0/'
  xmp:CreateDate='2020-03-01T23:19:51'
  xmp:CreatorTool='Pdftk'/>

 <rdf:Description rdf:about=''
  xmlns:xmpMM='http://ns.adobe.com/xap/1.0/mm/'
  xmpMM:DocumentID='18bbe863-be0a-4b2e-b22c-aa3209040363'
  xmpMM:InstanceID='49e92ac8-bf7e-4aaa-88f5-750a973838e7'/>

 <rdf:Description rdf:about=''
  xmlns:xmpRights='http://ns.adobe.com/xap/1.0/rights/'
  xmpRights:Marked='True'/>
</rdf:RDF>
</x:xmpmeta>
<?xpacket end='w'?>
font_00_sfnt_off0000e15e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE15E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF970 18920 bytes
SHA-256: 38d7bda3342a49f4f4a87922ad9555dc157792d821bd9dc6ecd01df9d107a1ae
font_02_sfnt_off00012ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AB2 10296 bytes
SHA-256: ac498e37833daf1eb32afc8e6a8c48933bf0b1ccca8d6201975665d59e882ce1

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