Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe611d2fc91cf622…

MALICIOUS

PDF

73.0 KB Created: 2021-09-30 14:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 4c8f9c0128f1672b9c71cdd8b6218133 SHA-1: 707e4cc1fe93327158743427e3d3f9a89bb3ed98 SHA-256: fe611d2fc91cf622cdeae40f7d57c7fad903cddff6dd308290a5a8292e7989fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to external sites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

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://wastran.ru/uplcv?utm_term=piano+tiles+4+apk PDF link annotation
    • http://dobrejaja.com/Upload/file/xudirakedujagagaki.pdfIn PDF document text
    • https://zakazspbwatches.ru/upload/files/13899781346.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/beditejinonorafemejo.pdfIn PDF document text
    • http://oikoscoccatoarchitettura.com/userfiles/files/kakupibaboselo.pdfIn PDF document text
    • https://verner.lt/images/files/9514569903.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/11691440045.pdfIn PDF document text
    • http://laiksmodalux.lt/app/webroot/uploads/userfiles/files/xekuz.pdfIn PDF document text
    • https://rheinfurth.de/userfiles/file/11634765483.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///kepef.pdfIn PDF document text
    • http://plechotice.sk/tmp/file/siwonovitolapenulivo.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/97204448169.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/17233630564.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/42044272025.pdfIn PDF document text
    • https://yourwebcenter.com/files/file/47518247147.pdfIn PDF document text
    • https://pvcmikser.com/upload/files/14905956692.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/1057475255.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/durux.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/49207261001.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/55364173987.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/105f17b4684a7272fc581f769c37bf42/danute.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147de3c82619---tigapoden.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/7634964047.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d25f542fb8---gilawefosoninofiporisegum.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/pewijetogutukidifiwewiziv.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/b975e6315f14cc07846468b11b8542d5/nejovobiganubomojubub.pdfIn PDF document text
    • https://tes-sys.com/uploads/ckfinder/files/20210903/16306145349091.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_off0000b84a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB84A 18188 bytes
SHA-256: 6da2b8a017005c891af292c3de5380e16bebf3b4894c1651e156aca5215811a6
font_01_sfnt_off0000e6e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E8 10316 bytes
SHA-256: 4f379e9786cace25de0812eb45650337f67bdb4799f2987133e53210989915eb
font_02_sfnt_off0000fe56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1