Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f935c5a39c5bb64…

MALICIOUS

PDF

86.2 KB Created: 2021-07-01 14:41:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0a65450ae639dc9de6977aaa20477eaa SHA-1: d256a381000e8c5d6eb5d56410dde74ef6d53714 SHA-256: 8f935c5a39c5bb649cea14e03b88644043155de313faf8ae4d8bba2595c8437a
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues about the lure, but the presence of many links to potentially malicious content is the primary indicator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://industra.sk/userfiles/file/13317434008.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077927d78e65---36544262130.pdf
    • http://interno-kazan.ru/upload/files/mupevitotototufofelenugan.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/k76rna3ntnqkie2t9l8mc6r7so/jibafa.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a95ea25910e---46781772315.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160beff2f792bb---71072779666.pdf
    • http://dichvuwebsites.com/media/ftp/file/zaxakazexokogiriva.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160b61d9f9f2b1---53586765453.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/952132484c8eea3156b48836e5088b81/84312820808.pdf
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086967513c61---mejorewidi.pdf
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/1f970f646f2d42e66f70da3b090256fe/gigulomi.pdf
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/7daa549c39ce949115440483e1833ef0/31655762152.pdf
    • https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce6bc7a140---18053144861.pdf
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/0ea69a089ebc6b9d753fa968f90ddd7e/vebafajunofareruxe.pdf
    • http://bephoangdung.vn/uploads/ckfinder/files/xodigibapojorujawo.pdf
    • https://btcauction.vn/hinhanh/file/40729648944.pdf
    • https://alshamiltrading.com/alshamilfiles/file/87761784578.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16073763d16fb9---xopam.pdf
    • http://youandisagenix.com/ckfinder/userfiles/files/57753914390.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160769957c6934---48691659666.pdf
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/e05019deb3cb01bbed033c5c61e7083d/vixebafidudelevam.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a84d3af6e---dulidulemoxizokozetovit.pdf
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/eef02accac14f1ad406af0926591d944/55202704843.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/4b560780e36ef3a089c18aac62de1b1c/33043759211.pdf
    • http://domingo.hu/ckfinder/userfiles/files/40606136937.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=buying+a+house+during+mercury+retrograde
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed27.bin
30fd05aee90139dfb8306f66819e12d2d37ac3cce30b0a6b9ac3626d1acc5c0f
pdf-font-stream PDF embedded font (sfnt) at offset 0xED27 17084 bytes
font_01_sfnt_off000119b1.bin
075f8bf6d08577a3e7624f1b0820695bd414a0e3aa38430f1cd8d60803d6b9fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x119B1 11040 bytes
font_02_sfnt_off00013318.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13318 16792 bytes