Malicious PDF — malware analysis report

Static analysis result for SHA-256 5911a15603c6bb34…

MALICIOUS

PDF

84.7 KB Created: 2021-06-25 23:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 5379dc6e0f2f00c21af2a428d297cc98 SHA-1: 4059b5446563e5f331f999c4b733ce040c3c63b5 SHA-256: 5911a15603c6bb34e3b6986b7ef1e8cafbd80eda266455e95b8e48fed04a7571
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or other disposable hosting. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to lure users to potentially malicious content or phishing sites. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://altelaw.com/uploads/image/file/mobefutavinudimitodatuzo.pdf In PDF document text
    • http://thedreams.cz/files/zasurixo.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c619bb24927---fonerazelupu.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb26d0c3c8---29413554410.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/gozemidasidunonag.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/6f833861f7e5c3362ab5cfc98e20c96c/xazulosuludujije.pdfIn PDF document text
    • http://gptools.net/userfiles/file/nanisikubufinovebanew.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/l620k6mqh57vpvonqqte4mkk62/98415695165.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/lokupof.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160befb7b239ff---zegeresomapoxudunaxuda.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/47489353530.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608bea23f2206---bebufiburav.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1608526e93e110---xokegufalixinirubatav.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a73f3de9deb---87442550793.pdfIn PDF document text
    • https://elesud.it/img_pagine/file/83636832153.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091be508ade6---25256406460.pdfIn PDF document text
    • http://runo34.ru/attachments/file/68125262748.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/162437613075.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16088507edfc9e---zudebamamosoxotezarevosek.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/iloct1caniojregra67n5g7dlb/niseninalelaxap.pdfIn PDF document text
    • https://pk-kuepfer.ch/ckfinder/userfiles/files/nupiz.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609be0767a022---91262342516.pdfIn PDF document text
    • http://portalkucharski.pl/app/webroot/media/files/pipatekeruf.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bb7ac278ed6---43516492937.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=design+of+reinforced+concrete+structures+notes+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_off0000e607.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE607 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE1E 10688 bytes
SHA-256: 181e8aa5c6ebaf3c0746a8d495f7d1067439a4978d77e16502d67fbb3ea28925
font_02_sfnt_off0001168e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1168E 17676 bytes
SHA-256: 86ba175ef2975e61228f04936a3145e3acf078b3f77c305f27ecba694a8c2451