Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcb8acf43082aae8…

MALICIOUS

PDF

80.8 KB Created: 2021-09-03 15:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f19ccc107da2ebd193887fca33a63c75 SHA-1: 2f14b906d6a4b76f1048eef72ab74f7035c0a59d SHA-256: bcb8acf43082aae89a534c12c2500650a88283efb05ad22e8648ba2ce5a90234
156 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://triosms.com/userfiles/file/71714906564.pdf In PDF document text
    • https://feltshoe.com/userfiles/file/72946741500.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da34e37858---dibulumimojafamudi.pdfIn PDF document text
    • https://evermoral.hk/upload/file/1629210652.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/dc23dh05gegum0mcc4ir3d6q2j/77229447949.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606deb761837b---73020096956.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/8aj8f4sfg7thadhc3h0tnphdf2/jazuxujivivefopofuguzivi.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/51481125714.pdfIn PDF document text
    • https://southwestlooms.com/admin/userfiles/files/xefufigiporaroguxuxos.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/61063209561.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/v1cvpm77p75jbq71u53th2kamc/7962494611.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/tbs7uhdg27qlmv2ja2bbogm03o/bofowixejuz.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c312f417a83---26322760946.pdfIn PDF document text
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/539d99d04695fc6adc93e9852908c99a/mudiguvekoj.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/fasidanupex.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/fb217cb02f3a92ca5f5686b25ce62a12/33152935295.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16089888593c5e---rofolisalo.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/90488045313.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb6fa09d2d---zemaxone.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608ee7f176857---vevogetanagepozigekodi.pdfIn PDF document text
    • https://michelbarbot.com/upload/files/roporavoduto.pdfIn PDF document text
    • http://dkmmotor.com/files/userfiles/file/31361082897.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/noriza.pdfIn PDF document text
    • http://scpt.it/userfiles/files/fufiresonusaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=mutomboko+ceremony+pdfPDF 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_off0000d8d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D7 10752 bytes
SHA-256: 7b47fc1f04b70ba669c26f45d095d0b8f64320872b26c49d4ccd0ed50ab87081
font_01_sfnt_off0000f167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF167 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010979.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10979 17048 bytes
SHA-256: 04e56fff1bde3959e92b3e7e3d03c1b16773ca9a9e0a564daf196a04f0620dc6