Malicious PDF — malware analysis report

Static analysis result for SHA-256 855a76c9c8ec4d9b…

MALICIOUS

PDF

83.1 KB Created: 2021-06-19 20:08:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 380db1238a18dced5cec91cca14a0701 SHA-1: e26f7e4539e1d06fbde1e9ab29135a3c42f7a406 SHA-256: 855a76c9c8ec4d9b5a27f673279f7a34c305d16c3fc0d14254961d318e88fd84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous external links, many of which point to compromised WordPress sites and are structured as a link farm, suggesting an attempt to direct users to malicious content. The document body, though heavily obfuscated, contains metadata related to PDF creation and search engine optimization terms, reinforcing the lure of a free PDF download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/09q8drgecosb6t11579c259scl/jovumelolosovunevitiwer.pdf In PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a86b686ea---55097856343.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8b8e1f3e78---10058277602.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606c87ec286dc---80947998967.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a1611ca20---parubezinat.pdfIn PDF document text
    • http://www.scsi.coop/wp-content/plugins/super-forms/uploads/php/files/816150e70001b8eeb7abb6888b4dae0a/75570902203.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607578b5b2c8f---68393399409.pdfIn PDF document text
    • http://asesorgubernamental.com/images/file/ximubojawudekajuvewonala.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160971b9501bce---8124148370.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/sofutuwodizexapud.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/37961474139.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/9917445e257cca6081af8f85930bfb91/72221638663.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/168ccd6901afcc4634c08ab9b96e2883/zipazivojena.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/673684b0c4275f817f930ccd755b362b/2479989005.pdfIn PDF document text
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/s3pa353f42vqhg7fn249ntnbmh/pesagagezimijomanas.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/ed85c4441d88c8eabc97d5cdc882aff2/dolivixotazotujemeteseleb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=critical+care+and+hospitalist+medicine+made+ridiculously+simple+pdf+freePDF 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e316.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE316 5404 bytes
SHA-256: e6cbaa7ecb6c76cc74e7fc83efeb0dff575f0dc7db2a681bf3817671926daf35
font_01_sfnt_off0000f547.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF547 11052 bytes
SHA-256: 59ffbaf0740fbec459081f31c07efcc8c6e538c6d9edf51c46590b0dec5da39c
font_02_sfnt_off00011af0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AF0 16204 bytes
SHA-256: 532315dfdc59b350d447ad91845dd8cc72a836e684f536ab9a4305dc5b53fb8e
font_03_sfnt_off00013020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13020 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176

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