Malicious PDF — malware analysis report

Static analysis result for SHA-256 511d38880b6da7ac…

MALICIOUS

PDF

84.0 KB Created: 2021-09-16 14:57:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: ba8638990125cc934a33357764286e4d SHA-1: 1a812b51515ea571b286a3ae224d8c1291fc4981 SHA-256: 511d38880b6da7ac16cc205fb7cfdfcb12bcbbab3caba278bda7f122107cfdab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, forming a link farm. This suggests the document's primary purpose is to lure users into clicking these links, likely leading to phishing pages or further malware downloads. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=online+novel+download PDF link annotation
    • https://jpt.mysmartedu.com/uploadimages/files/44625450831.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/zipud.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/428ede99aaf961179abec03660180dba/96366097334.pdfIn PDF document text
    • https://clickbox.ro/images/file/19468855676.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/14422111577.pdfIn PDF document text
    • http://transportdiverse.com/uploads/files/boxawefutexuxibokuxofu.pdfIn PDF document text
    • https://ww150003.linebot.net/upfile/files/20210902224409.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ecafa51756---80785168355.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/7291791867.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/82670715170.pdfIn PDF document text
    • http://ateliergermain.org/sites/default/files/file/nidunukiwowowa.pdfIn PDF document text
    • http://ohxto.com/uploaded_files/userfiles/files/2635205983.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/f772ac65b39ef84b4c8cf49aec019830/bibigubopu.pdfIn PDF document text
    • https://firmabudowlanawalczak.pl/web/uploads/files/67375297073.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/bureje.pdfIn PDF document text
    • http://uran-berlin.com/userfiles/file/vufuwinaruxakinazuvop.pdfIn PDF document text
    • http://48bulls.com/js/upload/files/vaxatafetutanuvefijulugop.pdfIn PDF document text
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/50411841135.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/35703859580.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e140f5372e---rujidosimagujeda.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613179d8ccea7---66481711966.pdfIn PDF document text
    • http://cocoabuterol.com/upload/files/tafexafamunex.pdfIn PDF document text
    • http://okna-kursk.ru/page_edit/_samples/userfiles/files/tosepirebisewub.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_off0000e5b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B3 10052 bytes
SHA-256: 9c4e3abb15e24585d6ec34c72ebef0e7dc72ca13162dce9772adbc1882f6cadd
font_01_sfnt_off0000fc2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011440.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11440 17764 bytes
SHA-256: d639c9972c4c3e242f45be48cacefd92cd4155e7e11c3191d4299b79623a6821