Malicious PDF — malware analysis report

Static analysis result for SHA-256 55e242a3c302cb51…

MALICIOUS

PDF

89.2 KB Created: 2021-06-25 19:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 18adcf59d80a191116054ff5991cda1d SHA-1: 673b21ae7b91bbb34fde50d128dbf067b9988299 SHA-256: 55e242a3c302cb51e824fcd23e54277d98313d7db5d953f11cea5e92f36b59a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a 'Pdf.Phishing.Trojan'. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. While no scripts were explicitly extracted, the nature of the link farm suggests an intent to redirect users to phishing or malware distribution sites, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://cgpreceptor.com/ckfinder/userfiles/files/32156878044.pdf In PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/ptdrpvrvqtpraskc3lpvsnbdji/farerud.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16088fff1a6fb3---beziboti.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/9t959vk8kj9mccjtla99t15gqa/sabas.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/10820754617.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/9a323f01466cee41de2996b10f4276bc/99121747696.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160758c48a3abd---50764345356.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/woninadezukalitexebew.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/82213352560.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4fdc23b26---varixagutugewizakifenupej.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/92280805083.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa044d2a68---40214277089.pdfIn PDF document text
    • http://szsahsh.com/uploads/files/30575550074.pdfIn PDF document text
    • http://brooklynsmokeshops.com/admin/images/file/3288759980.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/6jjqng01ui2ku9e9qf4fc0if00/19580185295.pdfIn PDF document text
    • http://pajurioverslas.lt/ckfinder/userfiles/files/6106119074.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/mipokekofimoxozedo.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/c719c32334bd4d69ece499e1b8fa1d63/22656310849.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/af4035e1e5fd5c55e0d64a94816ea056/dopur.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff12906a63---lajujosufewalenuzasonig.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///nitowunelolutubusude.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/266gf4ke5rsgfltge5b7foutu1/89350340029.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bunechgn5npv5g7fe9e7nflfa6/fixefofupev.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/d548a1a1325491379580cbb2270376fa/23160265624.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/lje192i7ehvqlstmcfsq1the15/983051088.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=striped+bass+smallPDF 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_off0000fb3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001134d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1134D 17488 bytes
SHA-256: 6d126b83b39c8ca85d9b98afda5bd6e8990a400fba8569955977053243862645
font_02_sfnt_off0001410a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1410A 10544 bytes
SHA-256: ff2d175c640ff8f774ca644ea0aa9570842305dde3ea7bd42950be3f9ca06f10