Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b100c58ad60c9ee…

MALICIOUS

PDF

91.0 KB Created: 2021-07-16 12:56:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: db9254a13600fca1e5fd7837d16ee072 SHA-1: 01b4495c9822c9438c65eed9614df19ee42d3c3e SHA-256: 4b100c58ad60c9ee2521b5b3a62f87622a191a57ddfd61f285555eb1e2a5c4ae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs, many hosted on compromised CMS platforms or disposable domains. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/suziveva.pdf In PDF document text
    • https://heks-tech.com/app/webroot/userfiles/files/39450622313.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/nusawudeno.pdfIn PDF document text
    • http://krakow4you.pl/krakow/files/vakijabikixuvibefudolejaw.pdfIn PDF document text
    • https://bonekarusa.com/contents//files/ladew.pdfIn PDF document text
    • http://timebymtm.com/upload/files/41097764812.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2ffeaa57d---1606137052.pdfIn PDF document text
    • https://nenanhduong.vn/Upload/files/julujolajoselavapiwoxoj.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/0c9cd2131e5c7a4c5a133bd1db60a2ad/67115341071.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d241ba1e9be---nevaxujo.pdfIn PDF document text
    • http://mynigaoe.com/upload/file/20210607192318.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce44fa5feb---xokej.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/5edd7de24041e3e4810d16bef7076495/godupivarerikebedefumofow.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/90a1398378f9e32c64c29cee9bb93ed1/16832104843.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/uu6kp6ms08fluv0arshmica53f/palebesipujivujekasikuke.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d780881f71d---35408887465.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/nomoribivudirejuminug.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/4005185a86ee3758af158f2bf4422df0/55081895494.pdfIn PDF document text
    • http://tykhestudiodesigns.com/clients/7/73/7311521ca682816632878891c231d107/File/kemubedejus.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/455e86c83a69a3078be4db550608295c/milerulujitur.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a099c587940---33498444419.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/pitopefabijinufuvuwupe.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3e7db6d93b---datupixatotejezumaxo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160867fcbcb571---65215300891.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/74515237589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=most+attractive+personality+typePDF 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_off0001028d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028D 10540 bytes
SHA-256: c33485eda3661b29d2a2708c70b072b803f93ef338ef8df7f7420e3f067d07fe
font_01_sfnt_off00011aca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ACA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000132dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132DC 17072 bytes
SHA-256: 3ff4d2ca8fc628dbe9f3061f293608bbb97802a9a6ead193038c388700de69c2