Malicious PDF — malware analysis report

Static analysis result for SHA-256 a36f83beb1278881…

MALICIOUS

PDF

69.9 KB Created: 2021-06-08 23:25:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: aab7186635d40dfddc6e4eda3ae9fcf4 SHA-1: b4b9482c11a651bcd83172906157ed56870e8aa0 SHA-256: a36f83beb12788816fdb614993275822e4cd2f2cda5e0a94be00b607c64a6e35
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous links pointing to compromised WordPress sites and other domains, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and compromised CMS upload links indicates an attempt to leverage these sites for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://chcial.ru/uplcv?utm_term=simpsons+building+supplies PDF link annotation
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bafcf226de5---zesulalugupo.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/16084a45cdebe4---kapebudesifolewixodipun.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160afc408d85c4---53308161036.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/9musrrdtvouafqp3hodi10qv42/53292054522.pdfIn PDF document text
    • http://garderoba.sk/images/_file/sevalarexibi.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3c544df82be595471242dc8228d2b8fd/xevifaravuve.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/226868caa24e82e96d551df5eaf93ac9/83360207215.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/dujatuxe.pdfIn PDF document text
    • https://advik.net/userfiles/file/87446469736.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba2296ca56---navesog.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/729bd89642346c15983ad757eb3b4fcc/lezejivopigabuba.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb958da395---kaveboburulelixivipubumus.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/jogawitulivelamerejafifuw.pdfIn PDF document text
    • http://ifa-astrologie.de/userfiles/file/fadadel.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/7946165d2eba4ff2182160d4d66f008d/kadubexejifiz.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5c70af31aa---pamakavozu.pdfIn PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/opb97vn83jcrad9k89hjo7nm1l/lunugomutisibazagidufe.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_off0000d20e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD20E 5216 bytes
SHA-256: 047f413ce7c4558b78656cd738ae7bfcb672980de9ef6c9ae7f385122f274ba0
font_01_sfnt_off0000e3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AF 11260 bytes
SHA-256: 0f13d422c92c38649b03061bf9410eccd6937509ea21a578da840bee0274eb4e