Malicious PDF — malware analysis report

Static analysis result for SHA-256 33d368cb00fc8ed8…

MALICIOUS

PDF

75.9 KB Created: 2021-09-04 15:16:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ada8f9a3b0caa1ce049e0614906a912e SHA-1: b14b6c93c6d72f8df2f242fb0ad1a641c61d2ea1 SHA-256: 33d368cb00fc8ed896d6781646a3ec1ae9fec0d21937e8714c683737cef554b7
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing text but containing structural elements indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://blnk.eu/userfiles/files/rositop.pdf In PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/ef8e793ef2635bf0a99ac03942761a86/2517442004.pdfIn PDF document text
    • http://kindergartenhelden.at/upload/file/jetazitisarodirul.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///84558591677.pdfIn PDF document text
    • https://www.phuketvillarentalandservices.com/ckfinder/userfiles/files/vawebe.pdfIn PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/wuwariwumukeveruta.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/gegirozezuvedareput.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/12025423422.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/towuvoxukafazemidoxedisi.pdfIn PDF document text
    • https://tonitomov.com/picture/file/mogoveloxonetolavafekur.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/e5423edfedbeb2ce62835258e8391f5c/zujozatajisaxax.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/g80gm7j5td06m248ubn26lcgpa/domilumametizogawig.pdfIn PDF document text
    • https://fundacjaartfreeart.pl/userfiles/file/fekuw.pdfIn PDF document text
    • https://warsztatgdynia.pl/app/webroot/media/files/goxosazodiwalodijudexedu.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/87495063828.pdfIn PDF document text
    • http://vsrru.ru/userfiles/file/wujukomaw.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/9c870b7e2d0c0514c04154932cdcd959/60939427101.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/3fc598c0d7eb0de8e6abeab17eda693f.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///fimimupimosobarigavaxeji.pdfIn PDF document text
    • http://mywymc.com/userfiles/file/guwupuwum.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a0c4c7950---51379489659.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/f3be970def50dacdcbcb67e0a4b50ef9/vaxus.pdfIn PDF document text
    • https://hogies.com/includes/template/uploads/file/22330943974.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=los+arboles+mueren+de+pie+pdf+version+completa+gratisPDF 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_off0000bf2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF2B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73D 18968 bytes
SHA-256: e5d09d997267b67e1887c5b8c25db9ca78c6f9924f09c4379b31a102975b2a40
font_02_sfnt_off000107c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C3 11224 bytes
SHA-256: c391b22a980bccac77eb405ecb75706dedfd2792bb739ec1d313e3ff0802deca