Malicious PDF — malware analysis report

Static analysis result for SHA-256 b91cd2b51f079714…

MALICIOUS

PDF

86.5 KB Created: 2021-06-10 05:54:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: f44d92ca1f54aa651819601d1585d679 SHA-1: 23348d1eafd88242d76de4946605dfef217023f1 SHA-256: b91cd2b51f079714114e0b08d4e907b69481b5cf41f1e7666eef8b1a34be3ccf
164 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to compromised websites and disposable hosting, suggesting a link farm designed to redirect users. The presence of a 'download button' heuristic further supports a social engineering lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=pokemon+x+decrypted+rom+citra PDF link annotation
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16092b8ff34e24---78848899385.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/37841188842.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/wasujevuge.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160840f15b8df8---2190875866.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/d7e5fe2944ac3813ab7fffd755d5bc8f/gemiramuditevemumurove.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608504f7ba80f---18851635270.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/36517167503.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba808a87c9---70360040928.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/297cdb607911eaffac7d1f4dc88dc608/51445652440.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077253b0f28d---24899201938.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/xijilolusufu.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c938494f31---53050807364.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983a262e662.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/d40e50e588b511b7501dcff0aa766dad/55497203488.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/74232060630.pdfIn PDF document text
    • http://balogmihaly.hu/UserFiles/file/texupezilufikizede.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000106be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106BE 5032 bytes
SHA-256: 6a52046ccac0f0d1628741daaa5df39524e0f5660c6156ebeb0315ee884ce44f
font_01_sfnt_off000117c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117C7 11836 bytes
SHA-256: de1cc868f9a739ecc710298b49c95d89eca30904ee09272b05a074c3b6116921
font_02_sfnt_off00013f10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F10 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3