Malicious PDF — malware analysis report

Static analysis result for SHA-256 81031bdd90fd960d…

MALICIOUS

PDF

82.8 KB Created: 2021-07-02 17:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 1457be9fcc07a0a07ce41d54d1788be0 SHA-1: bd106dab0c5c75f62760ece0eba9b70498b2ee61 SHA-256: 81031bdd90fd960d5f73a91f6565897196e9e314d89b2294c0dfae51fc94523b
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress installations, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is unreadable binary data, providing no direct clues to the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/428d886f82d6a88cb7d04c85aefad091/kokajafadopudalin.pdf In PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/c7c770d8009c81ae9cd6b5db783fd6f5/68897587577.pdfIn PDF document text
    • http://bora.su/ckfinder/userfiles/files/valoxuxegelaruzolifupage.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4fef853500---silizenirajaw.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/9dc79b4a30f0f93b3336b852d5ebc098/89729837127.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/99895117.pdfIn PDF document text
    • http://thebrownsfamilyreunion2008.com/clients/81208/File/37907577252.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/68905030227.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/e4b13737775c256144e60b118da2c16b/namopi.pdfIn PDF document text
    • http://marinapogon.pl/upload/file/53478912328.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/o1vmsb71naln3brm2h9v1r0777/rawefa.pdfIn PDF document text
    • http://rowanfamilyreunion.com/clients/28915/File/17044071322.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/99f855c7ae7d518a6e40973c36f64d07/menomobazale.pdfIn PDF document text
    • http://aiskreunion.com/clients/b/b4/b417c2091670ce0b0d78f4b231aea02c/File/79341326531.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/jabivorovufegi.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/arl0lreso0tnhjkitvjtfluo26/31772806486.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/jnm9lsdtjvkp9gqt7f6g1cf49u/51742140673.pdfIn PDF document text
    • https://textosolutionslinguistiques.ca/upload/editor/file/64258709167.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/5drrbbcvbshb9cf8d1j8cf43kn/27000786937.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/sikudugaroxudedut.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/0d8d535e4880667708a3c24243fc7b69/53522382380.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/4f3f52ddafc60372375bdad08354d0ec/91531515068.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffce7bd617---sunadiwuromanif.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081f68267d63---pisubezi.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b7d5a2f6e---14469128498.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/st69ja88emt96v4k27vl2koh62/5907130188.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=types+of+printing+on+fabricPDF 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_off0000de3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE3B 17860 bytes
SHA-256: c2e3068ffc4e15627eff1f7ff462d323bae409ee2dfc72251347202e14a06f3f
font_01_sfnt_off00010c9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C9C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B3 10824 bytes
SHA-256: 512ba8fbffc4343c020ddbbe64c6e3e62cb99a2bfeaf01d49dc3c00c2840ec46