Malicious PDF — malware analysis report

Static analysis result for SHA-256 83fb65085749445f…

MALICIOUS

PDF

81.0 KB Created: 2021-09-11 04:37:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c064920aac75f08007a571a5e6a09b1c SHA-1: 23b20a1e344687962a707042a6c66034fd8d7cde SHA-256: 83fb65085749445f4de89afd537dd66269c1f83138c58d8696536cafa811fe2b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and link farm heuristics suggest it's designed to exploit users by directing them to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9945

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://dermalab.pl/userfiles/file/zadil.pdf In PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/4btnio884ptj198u0mph12g5i8/24429811121.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/749906ef649c55d0988e43e5962d0620/92135672354.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/72507797500.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/jesopokisuvixudarubaj.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109020537043882.pdfIn PDF document text
    • https://sharkovinkom.com/sharkovinkom.com/ckfinder/userfiles/files/muponizukilozenikixul.pdfIn PDF document text
    • https://moulindelarroque.com/userfiles/file/36897150283.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109071503446734.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161354b85a49c9---56138145935.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/ticn5l630av7jmt3is5s25l7q2/selunowekaxapegoraniza.pdfIn PDF document text
    • http://keystoparadise.com/userfiles/files/sozefatuvoxaluraxigujurol.pdfIn PDF document text
    • http://space-edge.com/upload/files/benifanexunevixavoliseki.pdfIn PDF document text
    • https://airin.lv/images/userfiles/file/73341293030.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/694984e1a698a60fe1c5903e279f8f53/nasakagatesagexofukogogi.pdfIn PDF document text
    • http://ktcyy.com/ckfinder/userfiles/files/babozewufoworofu.pdfIn PDF document text
    • http://cissi.it/userfiles/files/81392495977.pdfIn PDF document text
    • http://bushurov.ru/images/files/kisebivoxox.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/buluxobaje.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/15684690373.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/66256614301.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/ralemaku.pdfIn PDF document text
    • http://zespolbahamas.pl/zdjecia/file/46586307644.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613b63840ad54---20891643867.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=retro+phone+themePDF 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_off0000d851.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD851 18452 bytes
SHA-256: 43507fb55e4c227f3df1089f345055dee843a8b25456baee6a0bdc90ea04057a
font_01_sfnt_off00010885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10885 10092 bytes
SHA-256: 2a700e1c89d539080c9bd36447f041e38a7c7f3dc621ef44b9b307cbe82416eb
font_02_sfnt_off00011ec4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1