Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b608579d611e7c…

MALICIOUS

PDF

99.6 KB Created: 2021-09-15 12:34:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0826b20bc130fa5a738e5188b13c1674 SHA-1: b17d4674ef0cc32ded73b0ef27cb0200b0182290 SHA-256: 85b608579d611e7c28bdfd4395d0e2697c189500166810f705555f1ee0a1dcc0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. The heuristics suggest the document is a link farm, potentially for phishing or distributing further malware, and the authoring application suggests it was generated programmatically.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 5

  • 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.
  • 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://coretry.ru/uplcv?utm_term=123movies+no+sign+up PDF link annotation
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/1630789456845.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/rerilaxafix.pdfIn PDF document text
    • http://onestep-tokyo.com/userfiles/file/46340393543.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/ruratenetaduj.pdfIn PDF document text
    • http://sangiorgioautoservizi.com/userfiles/files/marixokosufawixotesi.pdfIn PDF document text
    • https://bor-diing.com/upload/files/4966163938.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138387dc7ead---63168487305.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/bemusesopalob.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/fuvimul.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/57383433599.pdfIn PDF document text
    • http://enewind.com/pliki/file/bugelumogularowagu.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/wapebatevetipibirefirew.pdfIn PDF document text
    • http://hermanosgolbano.com/admin/fckeditor/editor/filemanager/connectors/phpfile/61208797265.pdfIn PDF document text
    • http://regmac.net/userfiles/files/gofevojevorel.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/gonozilu.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/46018610241.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/52959628108.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc83f8ac2a---dijuruzogebula.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///47698828635.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/666a5d5bba70eb6003935d1c5414f358/pemalatigavedizizurulokew.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/5033017293.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/93974722552.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/40434714007.pdfIn PDF document text
    • https://vieclamlaocai.vn/webroot/img/files/74134047040.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613a806de4cec---42745503853.pdfIn PDF document text
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011bfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BFE 10600 bytes
SHA-256: d7ba8da75c877616049c91f152a25d106230ca46bbd6fdfa60011a5922c8896d
font_01_sfnt_off00013445.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13445 19812 bytes
SHA-256: d7601bc65634b6f88b3fe695678749dbff52863f680bb0df9b12fc46226c0aaa
font_02_sfnt_off00016897.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16897 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1