Malicious PDF — malware analysis report

Static analysis result for SHA-256 56a23c181abfcf76…

MALICIOUS

PDF

89.0 KB Created: 2021-09-14 06:42:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: feff8a2998c75949ef34a9aa871a11bf SHA-1: 0f55cc96b05ec5aaa9665866eeeb14ccf88c640a SHA-256: 56a23c181abfcf768191c000a1d7e3dd69c6d276dfd1d76a90c5c9191599dc16
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm hosted on disposable domains. The primary heuristic indicates the PDF is a link farm, likely intended to redirect users to malicious content.

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://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c76091ac0---72792151459.pdf In PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/1421089970.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/54061572758.pdfIn PDF document text
    • https://tele-video.ru/upload/files/22638854935.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137237cd41bb---16733499557.pdfIn PDF document text
    • http://jungvassar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/10574622426.pdfIn PDF document text
    • https://afayl.com/userfiles/file/21262497711.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/161304dcf9b086---72318464933.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/161389b2bbe99f---wiguwutiruxifaxunalikif.pdfIn PDF document text
    • http://wildpflanzen-planung.de/file/22829199949.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/vamufotimi.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/fe7878b7a720715f71625966be522b7f/26191725290.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/san475ksd7dsmtf1kerk4md5lp/33183904277.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/gutap.pdfIn PDF document text
    • http://ilkconstruction.com/Images/Media/files/94270266244.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/6565996430.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/40224319691.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a867698aca---vekowo.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b1540d237---sugepuzugewisazatobi.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/lopamuverozox.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/vevadorodisugixi.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dipumasilixuxilukatub.pdfIn PDF document text
    • http://serting.eu/userfiles/files/8042519359.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/90394350695.pdfIn PDF document text
    • https://processwork.archerhuang.com/ConImg/files/kagimaradixowimis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=in+the+room+movie+watch+onlinePDF 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_off0000f957.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF957 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11169 17732 bytes
SHA-256: 4cce23ceed9cbc7932f3cca5675e5b5ed239533139f40a3b366d6dfdfff5c8cf
font_02_sfnt_off00013edc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EDC 10432 bytes
SHA-256: 2c527273934e4b2b1cf7da10d497e4ad7196b1a9fb78885ac6e4a4bdfef23b8c