Malicious PDF — malware analysis report

Static analysis result for SHA-256 936c3cfbb99911ab…

MALICIOUS

PDF

76.7 KB Created: 2021-06-09 05:14:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 4d4e51b5adfe53f57cbb5e78fafb95b1 SHA-1: 6818e1e0961db278a5cb07b81944fee852d837b2 SHA-256: 936c3cfbb99911ab99ce8bf3dba4f1010811c738c7fc3f0e7c30cdde76600c68
156 Risk Score

Malware Insights

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

The PDF document contains a link farm pointing to multiple compromised WordPress sites, likely intended to trick users into downloading malicious files under the guise of academic papers. The ML classifier and ClamAV detection strongly indicate malicious intent. No scripts were extracted, but the presence of numerous external URIs and the link farm structure suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://cructi.ru/uplcv?utm_term=mathematical+physics+by+bd+gupta+pdf+free+download PDF link annotation
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aabdf512648---52047660271.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160780954787ae---lelewujatogezeruwezow.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/300720d066a47bbfc0413ef05df69ed1/31241378767.pdfIn PDF document text
    • https://amatnieks.lv/pictures/image/5308678119.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/ecfb8b4a38c6daa895f138517dff2e9f/31996387901.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608a66b7aaa3e---3797046498.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/kinigadugovomuwizuminar.pdfIn PDF document text
    • http://ats-dz.com/userfiles/file/14640443450.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a32f35db7d---57246144536.pdfIn PDF document text
    • http://valeneighbors.com/userimages/9517500719.pdfIn PDF document text
    • http://whkmradio.com/userfiles/file/fibigapitelubewemomedex.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b855140e849---sobanaf.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/hmpo2k6q7es28e0amvt9frlm82/nivobufibijazuvoxofake.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/t95lt9nfnnepjt6ssteq0f915j/43294584522.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf960969c7b---matovewifuletononixuwufiv.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/1564536633.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_off0000ec5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5F 5908 bytes
SHA-256: 12e1408cf1225a6adceeecbde646e78b2f1dc6f97f057456069376567012140e
font_01_sfnt_off0001006f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1006F 10256 bytes
SHA-256: 57c02bab75abdc5ab8ed08bff38a8806d1d017276698f9ea99f6596d94be7333