Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7723e540915bfb2…

MALICIOUS

PDF

73.4 KB Created: 2021-09-20 22:59:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8b134797964817116fd8d972d4ec7533 SHA-1: 2272c70b6351cd8cfbe645fb9fe194abdf8626c2 SHA-256: e7723e540915bfb2ffa40704b6848bbcbf1641bc23bbf949885bfc81238668a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this, indicating an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://haisanquangninh.org/data/dulieu/files/79559878068.pdf In PDF document text
    • http://fuerst-architects.com/uploads/file/pikoregisinikimanudi.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/gga1v0h75eho6ceupj2661iv7s/98909821193.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/6201601068.pdfIn PDF document text
    • https://viboot.com/ckfinder/userfiles/files/32934079589.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/rezowofokimo.pdfIn PDF document text
    • http://luberoff.com/userfiles/file/musiz.pdfIn PDF document text
    • http://kcntanduc.vn/img_duhoc/files/getiginusomujugirarafezaj.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/8140624484.pdfIn PDF document text
    • http://lynhuagiasi.com/Images_upload/files/17397094418.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/pokalanetunez.pdfIn PDF document text
    • http://solee.cn/ckfinder/userfiles/files/jivoxabofuluzu.pdfIn PDF document text
    • http://charivne.info/images/file/dixixonixelutezebiluba.pdfIn PDF document text
    • http://hkbroadwin.com/userfiles/vaxobosiwimowulefex.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/pidimaf.pdfIn PDF document text
    • http://status.cz/UserFiles/File/zawufisow.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/xujitakati.pdfIn PDF document text
    • https://shoppingplanet.cityplanet.ro/ckfinder/userfiles/files/84087569991.pdfIn PDF document text
    • http://ideatity.com/ckfinder/userfiles/files/17283372532.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/67698057003.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161344ea79392c---xoxesovuxajatese.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370137213f3---dilubofafufagelixugoviz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=trash+cleaner+for+androidPDF 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_off0000bd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD1F 10436 bytes
SHA-256: 8aab7dbf001deaf9d219df488330a73c23a502a14f2609c80c1183dbf9fa1428
font_01_sfnt_off0000d4af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4AF 16932 bytes
SHA-256: cc20a60b4bc705dcaf6e43dc13ea18f6dafb9eb5a8b541fcd86e47ecd43e377d
font_02_sfnt_off00010073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10073 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1