Malicious PDF — malware analysis report

Static analysis result for SHA-256 4490c4438a70ddda…

MALICIOUS

PDF

93.5 KB Created: 2021-07-14 09:48:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 9c328fe6cbabb686678d7ed17cb6ece0 SHA-1: 46cba9e9f84ef6552c1b8360dd87cefc0dc8c15e SHA-256: 4490c4438a70dddadb64d158f95df4f95c082e81e33b5d269c1223f021eeefe5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious content or phishing sites. The sample's structure as a link farm on potentially compromised infrastructure suggests an attempt to distribute malicious payloads or redirect users to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9806

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://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607a82190aa2d---sewav.pdf In PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/nurobag.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/29juacb6mt4gdls3ulmflnm662/40178927049.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160895e1d92299---99965252445.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/750884abf1916b78ab9ab36383847cbc/petokowip.pdfIn PDF document text
    • https://pui-vital.ro/msg_media/file/22424139938.pdfIn PDF document text
    • http://momsystem.ru/public/file/38736476075.pdfIn PDF document text
    • https://akita-inu.lv/www/files/files/vopenefisewedukesaluwefe.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5b08078ed---3980841497.pdfIn PDF document text
    • http://celiapopememorial.com/clients/4/45/45605e685ba8a3b32f56966823665796/File/rafejuraf.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/e0500fd8cce0ca756a04f942fdaf4d15/zopojuvosesulobonag.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ap7rm60fefert86qdu7bo4e682/25294885328.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d249daeb7b7---zaxanipuzifolobufe.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091c580710d3---majumidedugedu.pdfIn PDF document text
    • http://xn--h1aaebbkfib4a.xn--p1ai/sadm_files/mobakakonasid.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec192ecfa7---57221361567.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160897498cc22b---20441162954.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/zupefemagitaruzogij.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/b4f58357cad50d35c677b4f6fcb8f51d/40371698420.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/b35dcce8da6ad3a07dc591d52130866d/24069174905.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/kevok.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/xobajavaperomedomuwam.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/21835285431.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/191275692760cf4d613da46.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/nalukofilinugezenalora.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608535da31922---96736941800.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/ae6mgv1kge5a21otq80t7km4a2/11443816898.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=real+estate+willoughbyPDF 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_off00010b90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B90 10668 bytes
SHA-256: 410558f59c94d465825455595fbefced5c0f853e4799b0c9710bfabd8f01ab03
font_01_sfnt_off0001243c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1243C 17112 bytes
SHA-256: 9c26c78ee5ba2e67664cd0134fe98b8507c98957bb3427151646db651d4e9e2f
font_02_sfnt_off000150a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1