Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bbb2e3f12b89556…

MALICIOUS

PDF

84.0 KB Created: 2021-06-25 16:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 107f7e704249f944f9d2eaa117ecfedb SHA-1: 9cf76fdf5120751a430ea80c64334c02126fcbed SHA-256: 1bbb2e3f12b8955624354e4823515fb1adb8d3840d473fb4160071256e6c229e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://infrive.ru/uplcv?utm_term=applied+mathematics+by+frank+s+budnick+4th+edition+solutions+pdf PDF link annotation
    • http://asja-doll.ru/userfiles/file/buvadelu.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa36aaa2d4---jipinumewotavuf.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/e6e057cffdf6cbb187bd53b8a318ee2a/jitolijewutiwidepaxami.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/powikajalesatamozegotave.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/94968692804.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/tiranuvuvetatitafekotuta.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/f1b0df87a9ecd7aa0d6ccb66db59ae94/31838593332.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/ribilopawuvapifemukise.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/19fa484fc7efd35d091de4a993858319/57442516807.pdfIn PDF document text
    • https://invest.pl/userfiles/file/94244053189.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/zatesurusifekurubokus.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/95583455115.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/967ac65efaa2efe213c9ba35cbf38e8e/mejomerixaguxuvisajuzuxij.pdfIn PDF document text
    • http://tvtamminhphat.com/uploads/userfiles/file/67656215512.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/htkarlen305crd86otm8eqiku3/4677548685.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC911 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE128 11388 bytes
SHA-256: 773a7166a53f1b675fccaa07470f60d9e7509c702b3fb11718da462a920e6482
font_02_sfnt_off0000fbab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAB 16300 bytes
SHA-256: cb22297cb345efa2b973a5529f7d34f362c2fa401ecec879e64cb16b1dda6a81
font_03_sfnt_off000111c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111C9 17692 bytes
SHA-256: cc096a128ef55b82a95a14f99b59f70cca6f1af9df2c8b275d476403d2cf7a72