Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4de2a4cae9800c2…

MALICIOUS

PDF

75.4 KB Created: 2021-09-18 19:47:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 988f5aa9dcb780f0acd4efb80916eed5 SHA-1: 3b0020430b2f5606dbc61c705feb8fcdca881b84 SHA-256: c4de2a4cae9800c2886019c4674bdc046fd7c0959a7fcf85181dc80ca4c3d562
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and link farm heuristic point to a common tactic for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://catamma.ru/uplcv?utm_term=mixed+conditional+sentences+exercises+with+answers+pdf PDF link annotation
    • https://chorland-dining.com/webroot/editor-uploads/files/zavujulixixusibegiwokegi.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/da78bef2a36c870f53bef9ab104447f0/73087857421.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/l3fbh6pld5i3cebdjs8k2i7bml/vugitis.pdfIn PDF document text
    • http://divorcefinance.nl/uploads/file/fifigapiwibidujere.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/f7c859dc2d448cf08144b195affe439c/90231828741.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/setilozumopata.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/95171364882.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/nubifaze.pdfIn PDF document text
    • http://edilcfcostruzioni.com/userfiles/files/15013661037.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/444434687.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161410db40d397---67276998333.pdfIn PDF document text
    • https://electroagro.es/pub/files/43544812394.pdfIn PDF document text
    • https://loctra.net/userfiles/file/5933839712.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/folewexamatunu.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/22525605367.pdfIn PDF document text
    • https://clarkfamilybuilders.com/home/clark/public_html/ckfinder/userfiles/files/38736491954.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/fikubitirodafaj.pdfIn PDF document text
    • http://josepholszowka.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gusigu.pdfIn PDF document text
    • http://katachizu.com/img/news/files/nitenedegofupedi.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce261aed4f---zewetewebifu.pdfIn PDF document text
    • http://maksimetall.ru/files/22090863711.pdfIn PDF document text
    • http://fxlcd.com/upload/file/43647532654.pdfIn PDF document text
    • http://medica-brno.com/files/35087921753.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/nobusidiribonudosapifakir.pdfIn PDF document text
    • https://betamachinery.sa/other_files/File/79032699832.pdfIn PDF document text
    • 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_off0000c1a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1A1 17368 bytes
SHA-256: bbece43f13d4c27ed00b03a72a08c7a1cf4da70c9d19ca211122f319e0f21b90
font_01_sfnt_off0000ede3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105FA 10896 bytes
SHA-256: 610da80cade7e18d3440155ea39f734b5bed168e27c0503ad38076ce622ccecb