Malicious PDF — malware analysis report

Static analysis result for SHA-256 41281d7fd2826473…

MALICIOUS

PDF

79.1 KB Created: 2021-09-10 04:06:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f65fbd7e553c3b9822ab118e9c1ae5a8 SHA-1: f86bcc3512f2854d1ae809f96a099b5c5c2c865d SHA-256: 41281d7fd2826473f7a106af6190ea5ca7cf842e37d794ed5286ccb2c57f5b87
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a phishing or trojan-like intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it is designed to hide its malicious nature rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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 http://zxpgw.com/userfiles/file/36390751788.pdf In PDF document text
    • http://studiotecnicomaglio.it/userfiles/files/xipetakufa.pdfIn PDF document text
    • http://joy05.com/_UploadFile/Images/file/juvodisuvulezoso.pdfIn PDF document text
    • http://prabashproperties.com/ckfinder/userfiles/files/bixagukepi.pdfIn PDF document text
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/16951826813.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/grmp8a55ctkbrop4c8j7l3irhr/tolonagegoli.pdfIn PDF document text
    • http://karpatskiles.ru/store/file/21618252252.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/wafojuvezoguzovefavonoma.pdfIn PDF document text
    • http://dges.in/userfiles/file/nofonefilakiwulaku.pdfIn PDF document text
    • http://rehahomecare.com/upload/editor/files/todixufavabu.pdfIn PDF document text
    • https://sapsda.com/SapmaUserfiles/file/98114655181.pdfIn PDF document text
    • http://lica-mpt.it/userfiles/files/kobuwenurovadup.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/58774003187.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/48344347836.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/43471446670.pdfIn PDF document text
    • https://adminico.nl/userfiles/file/7476555500.pdfIn PDF document text
    • https://tigapilar.com/upload/files/90656066300.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/mowenitot.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/retatos.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139445996796---migijavu.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/76139883413.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/63269845c1580c42faa3f7f1f03a91b3/wexaweti.pdfIn PDF document text
    • http://abwclayton.com/uploads/files/mudumaganere.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210904065146.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=latest+torrent+sitesPDF link annotation
    • 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_off0000d539.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD539 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED4B 17060 bytes
SHA-256: 0276d5f6ba29149604a1e4b26a32c7bdb716ed8746e7a161dabf3cda56b73194
font_02_sfnt_off000118dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118DC 10012 bytes
SHA-256: 63e14a3240c0b3ea05c694239555fc0158411ebafbb47093c78ff5884c53ab95