Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef796b90e756056e…

MALICIOUS

PDF

86.1 KB Created: 2021-09-22 15:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c5706581b892dd7a1291cb5881f9db2b SHA-1: af53062f183df032cf6e59508a21510a99c7f775 SHA-256: ef796b90e756056ed6bc550bc463c48b12cc7db3c4bf627d9427fccc8e7bcf76
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress sites, suggesting an attempt to obscure the final malicious destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/bt9rtlik70g7nknktppg5tk0f5/41178912478.pdf In PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-9-2/20210902112412783364.pdfIn PDF document text
    • http://lingeriedediva.com/UploadFile/file/2021090701243373499.pdfIn PDF document text
    • http://arsvet.ru/img/upload/pebad.pdfIn PDF document text
    • https://hoangphatdanang.xetnghiemadndanang.com/uploads/image/files/75505940015.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/jilamitakisewuwumibakaze.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/rikiwobowexofupevawaj.pdfIn PDF document text
    • http://aluminial.pnh.pt/js/ckfinder/userfiles/files/32075018919.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/dddf7bc5a762109e34d6fb612cd34acf/rixuvube.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/74412100683.pdfIn PDF document text
    • https://cooperspick.com/files/kifodamawipo.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/25636546872.pdfIn PDF document text
    • https://aronabritcan.com/userfiles/file/11653063254.pdfIn PDF document text
    • https://hamayeshniroo.com/shop/file/71067884941.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/82197272510.pdfIn PDF document text
    • https://www.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/vubuzakez.pdfIn PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/23705598680.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161435de237379---2592923048.pdfIn PDF document text
    • http://ohdiabo.net/images/ckeditor/files/96638702397.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/58504200840.pdfIn PDF document text
    • http://vivaibonomo.it/userfiles/files/ganuvidanowewa.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/76493913443.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=online+histogram+chartPDF 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_off0000eb21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB21 18572 bytes
SHA-256: 3af719803ac0f249ca75dac5ba9b821fb4ccd7723cd33e2f49f751fbe6075fc1
font_01_sfnt_off00011a92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A92 10704 bytes
SHA-256: e320018bfc58562588c9de5de5c8485f3acbcc5ab6e300983250d766b867b6a5
font_02_sfnt_off00013300.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13300 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1