Malicious PDF — malware analysis report

Static analysis result for SHA-256 18ba245149777ca3…

MALICIOUS

PDF

74.5 KB Created: 2021-09-17 11:34:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d74cf912267d08509ebd9c51af444dc0 SHA-1: f20dcc5d27c67425a28221990fba71ce5a112e58 SHA-256: 18ba245149777ca3611e46c2f7fd27eb43cffa2796e5ce1a6433cc2647f61e5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised or disposable domains. One URL specifically points to a WordPress upload directory, suggesting a technique to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 http://zjgjqmr.com/v15/Upload/file/202199648371011.pdf In PDF document text
    • http://fratellilongoni.com/userfiles/files/lemakexofuza.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/seketotofogiv.pdfIn PDF document text
    • https://daulte.com/ckfinder/userfiles/files/novuzovipulilivipedi.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/88023197537.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/32293055309.pdfIn PDF document text
    • http://mixline.ru/img/lib/file/71017290765.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1a3661062---89254301921.pdfIn PDF document text
    • https://on-call-anatomist.org/ckfinder/userfiles/files/66418998931.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/8db20f5e14f6bb15e6c92250ef425fc5/sobexidazuzemivigajoj.pdfIn PDF document text
    • http://tangiahoang.vn/Images_upload/files/255568230.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/noxanixibupodegexutasime.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/mixewuvamukemewubuja.pdfIn PDF document text
    • http://naplesredeals.com/userfiles/files/83405821941.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16140fc38166f8---zinapixoxapoduvivuz.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/bb4731469c89785e061ed786d9b7d47b/43996058714.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/dofanabafumususareme.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/xapifurapoderajeramo.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/ruxogaxusajowesegu.pdfIn PDF document text
    • https://termoformat.md/img/files/kigibon.pdfIn PDF document text
    • https://windsbs.biz/files/file/95603635046.pdfIn PDF document text
    • https://ysh.my/userfiles/file/61571992963.pdfIn PDF document text
    • https://iwanbim.com/userfiles/files/papufawobawowigomefiz.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/36150917240.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/92899949247.pdfIn PDF document text
    • https://peperita.it/writable/public/userfiles/file/47234619968.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=how+to+add+emojis+to+whatsapp+iphonePDF 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_off0000c1b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1B8 10720 bytes
SHA-256: bf7edeaf0ece3153c901657f1dd59d42a1d6fed4ba78c5953136918e7d4456cc
font_01_sfnt_off0000da20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f232.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF232 16240 bytes
SHA-256: a7f621c6fb76f99aa6c7aaa8e4bb5e3a9b76bdb3fbebb8e003d4731556d8eaad