Malicious PDF — malware analysis report

Static analysis result for SHA-256 21a0c78d84a077f7…

MALICIOUS

PDF

87.4 KB Created: 2021-09-16 16:37:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2bdde8ea0fff207684e0f66340984507 SHA-1: da8ea7182cb699c6adeb1448d550a23997207517 SHA-256: 21a0c78d84a077f771bcaf5ef1af1cc8b7796e384145875521490110dfaced88
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous embedded URLs that point to various domains, many of which are identified as link farms on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. The presence of external URIs and link farm heuristics suggests the document's primary purpose is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://synerhu.ru/uplcv?utm_term=modify+game+values+android PDF link annotation
    • http://bidmitt.com/img/files/file/68185702356.pdfIn PDF document text
    • http://ex2010.com/uploadfile/file/2021090114333973499.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/jejutax.pdfIn PDF document text
    • http://parquet-cortes.fr/data/Files/dalivotagokiwopudesoxeka.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/96276235257.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/33141461211.pdfIn PDF document text
    • http://tencanpowder.com/d/files/rajerovugaxanel.pdfIn PDF document text
    • https://middletonchambers.com/ckfinder/userfiles/files/26483296245.pdfIn PDF document text
    • http://giadinhmedia.com/uploads/files/nimasigijixedilirin.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/f77c44db141b032d1617c6a9c7c43531/zuriloripatudomo.pdfIn PDF document text
    • http://xn--c1aejbdnke.xn--p1ai/admin/ckfinder/userfiles/files/sedepanotemufotu.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/18692337050.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/88408828805.pdfIn PDF document text
    • http://esipro.lu/userfiles/file/jamotibexonumomitavozi.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/4u6cuquij69lgih1aen1610mj3/82718412205.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/83627790452.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/sivitaz.pdfIn PDF document text
    • http://yh-nutri.com/filespath/files/20210902012342.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbe99656bd---dagez.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/napimepipumekemoxipiwa.pdfIn PDF document text
    • http://fxlcd.com/upload/file/10499866335.pdfIn PDF document text
    • http://michaelwilliamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zetaloweg.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010abb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABB 10872 bytes
SHA-256: 23d990c1bd1039e48687d909eca934a60ced173ba831f91ece2b2e98e6bc7550
font_02_sfnt_off000123a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123A6 17296 bytes
SHA-256: e3570051825cfb90f0cc8d669d29470cc77847cb486d6dd862006fe559124f37