Malicious PDF — malware analysis report

Static analysis result for SHA-256 43b34fa42e2e51d9…

MALICIOUS

PDF

85.8 KB Created: 2021-06-17 18:37:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: e4b61c01f151e5f29240490adfb6fe0b SHA-1: e5e0c6eb5013dc8a9188cb14b42681a77e77b874 SHA-256: 43b34fa42e2e51d9a90ba7262d72434375df346d8a5c764c5fceec0345a1a669
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of external URIs and link farm heuristics strongly supports this attack pattern.

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://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/hdp9a4fi6r5c5qados14m5rt2s/30614789816.pdf In PDF document text
    • https://kurek-rowery.pl/user_pict/file/zesosijuxuwigafutetiw.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/rir9kcmbb99o5utc1lqoj6u98o/nezoni.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/b2b327af9ce04b92a003539e470eb6fa/43401946977.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c899d8f375f---7845137332.pdfIn PDF document text
    • http://jarosi.hu/files/file/35068044770.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/um9s862lf67lm7nq2v6m76t3n6/nosoxutan.pdfIn PDF document text
    • https://werbemittelag.ch/upload/file/53339996923.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/b242226cc6da74929c7370b5bab1c8e2/pixegazuneripiv.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c62e066e17d---71607848597.pdfIn PDF document text
    • http://markone-tools.com/upload/files/nuberodusixa.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da32b90dd9---82039136163.pdfIn PDF document text
    • http://budoprojekt.eu/obrazy/file/fajodu.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/83a08f608903425cc9d4dec2311ab0d8/85682072975.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/39688762600.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=all+android+games+mod+apkPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000106b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106B8 5040 bytes
SHA-256: 0085747f7fa5914e5d8dffd24a2baaec70d3f9935a875ec32875ac2c2fe98413
font_01_sfnt_off000117b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117B2 10700 bytes
SHA-256: fffbd86f0d358cf3a27b9855b220290f5b123f107c86635dfb44b68eaafed02b
font_02_sfnt_off00013c0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C0B 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34