Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e79a681a460658…

MALICIOUS

PDF

70.1 KB Created: 2021-06-10 07:00:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 78c4c5a8ccbabe8f2b5966d8c40e53c1 SHA-1: 9b34d331d12ec44fcef094fadfced70e07af1f6d SHA-256: 50e79a681a4606589c6d2df8cb73ebe3d85e0ce81a383cc56aaf7e8ae9af0495
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and numerous links to external websites, many hosted on compromised CMS platforms. The document body, though obfuscated, suggests a lure related to 'worksheet answers', indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://crysiq.ru/uplcv?utm_term=angles+inside+and+outside+circles+worksheet+answers PDF link annotation
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/a1e970aa43aa1727aed58cf59af178db/96769595883.pdfIn PDF document text
    • http://incucinaconalberta.com/userfiles/files/80728411268.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b8db12bef5c---34481297875.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3369c1cba---51997462565.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160afd33ca53cf---18152217099.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/21958c8dd72da3c539ff59af6ca11898/rubud.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f067d16704---4536910449.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c0d58596c18---midura.pdfIn PDF document text
    • http://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210526122602735830i81rzr.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/6b3ugfh3tkvej1q5hic2lr0bg6/69472394073.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae6f54032be---58096515231.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089d401cb9f8---7427664573.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f45f07a8b---zozedopatajotugiwegafizom.pdfIn PDF document text
    • http://royalwedding.jp/images/blog//file/gefabekofi.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/da12a12c37bf441575998fa066006417/gagoraribix.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/286dec75609acc5d61e9698578872374/rofopoxud.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57D 5348 bytes
SHA-256: 2715244a504c03100f9294b3e67394b31ff4f805fef1c57fe7599944f1e5dd50
font_01_sfnt_off0000e7bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7BB 10472 bytes
SHA-256: 0c6d2f9bc46f61f5ff4ca9eddc5b957bbe69bc7d722d221a45f64ca9e121931a