Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d91fd0f5798e8a3…

MALICIOUS

PDF

86.7 KB Created: 2021-08-14 05:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-16
MD5: 042aa574f7a2ed29651109efb9a9686a SHA-1: 54156a3418fa1d46ec176db46b3b6e55bd261b20 SHA-256: 3d91fd0f5798e8a31eae1310097660b29dfef05eaa728d527c788a08757b72f7
164 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to distribute malicious files. The presence of a 'download button' heuristic further supports a lure-based attack. ClamAV detection and ML classification confirm the malicious nature of the PDF, likely serving as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ahxxzx.com/userfiles/202105/file/mofivalosedujoxupiwinedu.pdf In PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607594933e274---jafaxadalam.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a35c0b2e195---65457387219.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e1278752c---7756911750.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/99542a47f0be777b5fe2f16d4cf7b17e/wajemalaxupo.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/bonoxulavowefuluduzis.pdfIn PDF document text
    • http://planbmedia.hu/files/56305914378.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/7510287506.pdfIn PDF document text
    • http://zonwering-nederland.nl/ckfinder/userfiles/files/keluxalazobirem.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/84924655578.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/37727544854.pdfIn PDF document text
    • http://krupongs.com//images/file/ruvil.pdfIn PDF document text
    • http://khanaphatgroup.com/UserFiles/file/lolowu.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/eda6e527c2fc4bf591e669c2f84b455d/52889962662.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/lewubividifufabonu.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/pexabezevufone.pdfIn PDF document text
    • http://ghgunclub.com/clients/f/f3/f3036db30fa8ed97f94f648fc77c1040/File/85110638944.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2a2fc914f---femosubobow.pdfIn PDF document text
    • https://landi-bg.com/images/file/85883978699.pdfIn PDF document text
    • http://orderkai.com/uploads/files/kupujarobovilasabukol.pdfIn PDF document text
    • http://belgium-ex.com/images/blog//file/66991274083.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1606f2f962533e---15459372207.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/peperom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=mini+militia+2+hack+version+game+downloadPDF 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_off0000ec5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5A 17332 bytes
SHA-256: f4579588ed92f749b713c161263d816ecfb273c16d1bef84cf48d0412e4afd51
font_01_sfnt_off00011894.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11894 11172 bytes
SHA-256: fe99cb59b21b6910c9c9ede59d4e14d3ac3fd4b1fc72a18620c5d60110c3642c
font_02_sfnt_off0001326a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1326A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1