Malicious PDF — malware analysis report

Static analysis result for SHA-256 57bbf42548b33a3a…

MALICIOUS

PDF

74.0 KB Created: 2021-09-12 23:24:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d68886dfd479caad8901876c436dc4e4 SHA-1: a0ea619106e242ee653bc3007f0f5a01d7b0d768 SHA-256: 57bbf42548b33a3ab648aebd85acf99e59c5a4694f6f3cb52ca19246a6b5c052
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Numerous external URIs were extracted, many pointing to potentially compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://cec-intl.ru/app/webroot/files/file/51188231521.pdf In PDF document text
    • http://immopolignano.lu/images/dobitatukilesuta.pdfIn PDF document text
    • http://reklamavysocina.cz/UserFiles/File/74397231730.pdfIn PDF document text
    • https://hargagila.com/uploads/image/files/bixopejasosexolevil.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/9lsna99dv1geu387fct5ltpn27/57483860357.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/coqs6lld611j031r2aavr3gj4e/86761334773.pdfIn PDF document text
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/12963746699.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1631402398.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/50611046047.pdfIn PDF document text
    • http://sjhtractor.com/d/files/tidugutoboposepariri.pdfIn PDF document text
    • https://polenhosting.com/calisma2/files/uploads/dotusagelubetitubizofupuz.pdfIn PDF document text
    • https://www.pepinieres-gey.fr/ckfinder/userfiles/files/sigix.pdfIn PDF document text
    • http://como.gattinonimondodivacanze.it/themes/userfiles/files/63583195607.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210902/files/20210902055318.pdfIn PDF document text
    • http://balone.net/_upload/file///27815200314.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130215e8a72f---ladawefemedifezavuw.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/3498752217.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/ef18bb51047d3520bcb3b9376860d754/jozotobisamelupitin.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/jawilovebugozabu.pdfIn PDF document text
    • http://sipsak.nl/userfiles/file/45338519473.pdfIn PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/5908858883.pdfIn PDF document text
    • http://demo-calson.garment-pro.com/ckfinder/userfiles/files/verojewaxikinanozob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=team+dragon+apk+downloadPDF 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_off0000bbd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBD9 18048 bytes
SHA-256: 817b25e61ecc4add78b4d052dc837a5915c924af11a01b877cb1b84f97334210
font_01_sfnt_off0000eb11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10328 10516 bytes
SHA-256: 9095e59c7f2e08f00a32c7ba1737787a853d4cb44089a8c18e16c79e6e64fd1f