Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b38bd8ec74e8bb2…

MALICIOUS

PDF

82.8 KB Created: 2021-09-15 14:25:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 42df80adfc327fec760314a57f1d730f SHA-1: 83d61eabc6473bc41da0dd9179bcb2fd63bbd490 SHA-256: 9b38bd8ec74e8bb2fcfdb91f5bae58f71e0cf0b6e716374c35c07947e0902d79
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external links. Several heuristics indicate that these links point to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • 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.
  • 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://synerhu.ru/uplcv?utm_term=cannot+deactivate+device+administrator+android PDF link annotation
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161398081ce165---nivuteti.pdfIn PDF document text
    • https://svltv.in/userfiles/files/55378934219.pdfIn PDF document text
    • https://denimder.org/resimler/files/7298989928.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/42714524152.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/rexorateledodulonu.pdfIn PDF document text
    • http://vipnovini.bg/root/f/uploads/files/kufuligifon.pdfIn PDF document text
    • http://mskabel.cz/UserFiles/File/52318520293.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/94534290340.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/rukuximan.pdfIn PDF document text
    • http://yangpupark.com/uploadfile/files/juresezozarov.pdfIn PDF document text
    • http://chongros.com/userData/board/file/70527215491.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/11662767901.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/3160258632.pdfIn PDF document text
    • http://www.sosonomo.com/ckfinder/userfiles/files/sikavofebemivofumona.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a286d222d---56416838028.pdfIn PDF document text
    • http://carneiro-sa.pnh.pt/js/ckfinder/userfiles/files/zuwuwuvibot.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/97674132932.pdfIn PDF document text
    • https://lwim-ouargla.dz/ar/files/53536539321.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/mosos.pdfIn PDF document text
    • http://saigonford3s.com/uploads/2021-09-01/images/files/48893148190.pdfIn PDF document text
    • https://talaa-obour.com/webmisr/uploadwebmisr/file/58818204136.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/4536319002f7bcc12236cfbaabdfcb35/99664291212.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_off0000dd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f58d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58D 18148 bytes
SHA-256: 8f6938435e0aae2c787281d4951a774faa2e2b09aa0bb627e20d8a5fb53842ae
font_02_sfnt_off00012545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12545 10580 bytes
SHA-256: f5ae48b1c2b3734ae8aeb7f7b356f983c16433a3714571dde47875f5664c1052