Malicious PDF — malware analysis report

Static analysis result for SHA-256 90bea6edfc65ae4e…

MALICIOUS

PDF

81.9 KB Created: 2021-09-11 15:30:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1d3273fa678ff919081362aa42e3bac3 SHA-1: 021ddca099c10f78d3019f12d95731971af77ec0 SHA-256: 90bea6edfc65ae4e5262119cc6187b008ccf3385876721253e2731ad83860b40
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or are part of a link farm on disposable hosting, suggesting an attempt to lure users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing metadata consistent with malicious PDF generation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://blueview.nl/app/webroot/files/userfiles/files/71121466198.pdf In PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/29151737983.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/42017003965.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/sadinokobotidarega.pdfIn PDF document text
    • http://client.diffuse.info/files/28696617242.pdfIn PDF document text
    • https://magiccat.pro/ckfinder/userfiles/files/wetidajotav.pdfIn PDF document text
    • http://naso10.com/userData/board/file/bivapogelawivawekofakor.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210901220459_k522cp.pdfIn PDF document text
    • http://glavis.biz/userfiles/file/voxabujolinikixodut.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f56ae58be6---lemoferikebi.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/lemabemipu.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ace1df3fd6---11205771542.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/83199640628.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210901_FCC34A1ADD7068BE.pdfIn PDF document text
    • https://imagebrandstudio.com/userfiles/file/553238712.pdfIn PDF document text
    • https://ecoquimica.cl/dinamicos/uploads/file/kolosuvitif.pdfIn PDF document text
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/71689101412.pdfIn PDF document text
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/82518190524.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/5223846786.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/kapuduwugugadoredutuf.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/76440149204.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a778e1f1ca---12379065050.pdfIn PDF document text
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/lokinoti.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=common+nouns+that+start+with+vPDF link annotation
    • https://www.posluh.hr/ckfinder/userfiles/files/77527686173.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_off0000df4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4F 16660 bytes
SHA-256: c6066deeb3de31321b36a87087a39d03c699f8394a4e9863676b99bdc32a2e6f
font_01_sfnt_off000109ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AE 10476 bytes
SHA-256: 89ca83944473043cdeaffb0904801057044ccc9995fc150762693e4293ec2e13
font_02_sfnt_off00012162.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12162 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1