Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55fb752a24e96b7…

MALICIOUS

PDF

79.6 KB Created: 2021-09-10 15:29:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 76b99c8e4d8392bf22d2ce3a30b8fe21 SHA-1: 2acca20e9649a512c351cd29748e3c7b47effa34 SHA-256: a55fb752a24e96b76cbdf8519ceb143a4cc48f0fced7728d1440da6de3038b08
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://infrive.ru/uplcv?utm_term=keyboard+exercises+pdf PDF link annotation
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/15af0e413aa57a50a9005eefc1027e5b/31641758441.pdfIn PDF document text
    • http://salman-group.com/userfiles/file/95564429.pdfIn PDF document text
    • https://gad-elhak.com/userfiles/file/kiwewizefisuvapemo.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/67205367687.pdfIn PDF document text
    • https://underworldgear.com/admin/images/fckImg/file/kasowaruxudejokakodobif.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/wonunovuvasipumefa.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/sosadu.pdfIn PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/xubibupugenerovidu.pdfIn PDF document text
    • http://studioprogettoarchitettura.eu/userfiles/files/motafuwoxik.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/681b4e6737f532c8a3b88f57b1c20905/8403863984.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/59501580674.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/41209236246.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/f155b54263502f530c3730be10f1d856/fukiwubowofisokekal.pdfIn PDF document text
    • http://peoplefineart.com/assets/202109/files/20210907024703765133.pdfIn PDF document text
    • http://jwconsult2005.com/file_media/file_image/file/80948038987.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/rimafifuzusezevokeg.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/fozifab.pdfIn PDF document text
    • http://rubella2.integra-sh.com/userfiles/file/zawilasuwexedixe.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/takesonezil.pdfIn PDF document text
    • http://cantinachitarra.it/userfiles/file/pasomonopozujate.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/pubere.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16132350b797bb---kemalelunuxifaluvuje.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_off0000d216.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD216 10712 bytes
SHA-256: 7fb19c558b267822b4212931d2d1e342a4683a2b33a6a890e414d67475ee8c5e
font_01_sfnt_off0000ea9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA9E 17660 bytes
SHA-256: b731e6c81c5483396113ea37ec33da6e20fb6e79c493e80187ca41660ed5089b
font_02_sfnt_off0001189f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1189F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1