Malicious PDF — malware analysis report

Static analysis result for SHA-256 81256b92760e1eb8…

MALICIOUS

PDF

73.2 KB Created: 2021-09-08 00:57:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1bd79cf34e9037e01facbdd446b20759 SHA-1: 8e073733f1a94efad03537cefe79b4d4540809b1 SHA-256: 81256b92760e1eb8fa3ad8866ff31cfb1b2c2bceea5cc2ead8a0af98c5bda411
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or trojan delivery mechanism. The document contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm or phishing lure. Although no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest an attempt to redirect users to malicious content.

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://crysiq.ru/uplcv?utm_term=zanussi+no+frost+fridge+freezer+manual PDF link annotation
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa14e8884c---93321773725.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/7545e1d7159f13d505a86d523bbcf56a/84103537004.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/4lb8g3ke6omvg2csb98ftkdv2j/33470927922.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160dfcf2a9bdb4---vavejojediropavugej.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/19650702089.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/gusowenazisizagedulekop.pdfIn PDF document text
    • https://durgabas.coop.np/ckfinder/userfiles/files/79845895280.pdfIn PDF document text
    • http://tcyy88.com/userfiles/file/2021082206181573499.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/27409484449.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607125081dd9a---sevezanunugewo.pdfIn PDF document text
    • https://mwasafat.com/uploads/files/47852619667.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/wowebifopakuzux.pdfIn PDF document text
    • http://king-tableware.com/uploads//files/202108031117355297.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/3616317388.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a28738ed2a2---74115989396.pdfIn PDF document text
    • https://proxus.nl/file/jipibawuxezugurufuka.pdfIn PDF document text
    • http://thietbixanh.net/uploads/files/46244313956.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/i5c29sgggntivuuuo0igmlmi36/7410047267.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077337f208d4---33846612940.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/0qgnl0a0vfitad45luf2vlk036/80190717003.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/7404027754.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/23484494946.pdfIn PDF document text
    • http://prospr.fr/ckfinder/userfiles/files/9010730557.pdfIn PDF document text
    • https://webdatedepot.com/userfiles/file/mokabutazuziwo.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_off0000bdc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDC7 10820 bytes
SHA-256: 9625e5ac759d391650bf0e4c0283a75e73c9fb33efc9709c4917b141ad5d4f7b
font_01_sfnt_off0000d68e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68E 15616 bytes
SHA-256: 11d6bc0708cbeb8ad9095a183f02941aae098fe6841c7b4fbe6ea26c5cf14ae3
font_02_sfnt_off0000fee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1