Malicious PDF — malware analysis report

Static analysis result for SHA-256 31eeb77781e4e659…

MALICIOUS

PDF

81.9 KB Created: 2021-06-12 21:52:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 43e83882ecb532464e6e1f2ac94d067d SHA-1: c1b9808654b0dbc6048f00e669fb9947ad07f2c3 SHA-256: 31eeb77781e4e659890ba1b6f07df84b65ac95ea44b09370ac5128fe37e69363
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://philabc.ru/uplcv?utm_term=dieta+para+diabeticos+imss+pdf PDF link annotation
    • http://petraifevronii.ru/ckfinder/userfiles/files/zudizesiko.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bb817097f23---61135967508.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab60966cfe---23902323167.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/c176f73f4d94c2dfe22f8cdb5b9f3975/gixuge.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/1f3a51c12124ac36331d3a43e8ca2bab/90944413941.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/005536ae84e52f293eaa8677d26e0e66/jopijitiranapewivup.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/29c3ebf8a4c847fa33e145119a4cc2f6/72078905441.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/5399687624.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f4ea5afba---70552122448.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/63938594739.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/3b7v595ai0tdbar6hr2t7484ge/xozodiguwavizuduge.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba873cf131---pefuvemoxutan.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/35c7e865a3dcb4205c36d36fe8fa20f4/5158234406.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/90303251e34139739a19f25548a8bd61/vikonej.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/wezekikuvarajevonodow.pdfIn PDF document text
    • https://taxiporec.top/wp-content/plugins/super-forms/uploads/php/files/n45m6s291ia4pkuvujl0n8pc39/8436160764.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/fekewawetujo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fe72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE72 5408 bytes
SHA-256: 259120ff9fe5f4985220dbe005b7e751c14033777d1172d49ac1e95f68585f0f
font_01_sfnt_off000110c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110C1 12428 bytes
SHA-256: 740c632402090762f34830a26f793fdb44a962effb62fd896c9aee2078ffaa66