Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3313eaa58e0ca1…

MALICIOUS

PDF

79.6 KB Created: 2021-09-03 05:03:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ca4d953ec92eef53517d4d8bf1d7a4eb SHA-1: c4d3b0ed59a2353e15d0e38fd4168921b0036d3f SHA-256: 8b3313eaa58e0ca19c286ce09924fff45db9f43e4c27352d0613a8f19085f809
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to PDF files hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of embedded JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://chcial.ru/uplcv?utm_term=download+eksu+post+utme+past+questions+pdf PDF link annotation
    • https://cultureresortpokhara.com/assets/userfiles/files/89636773677.pdfIn PDF document text
    • https://vegas-shop.net/uploads/files/joberawujakujuda.pdfIn PDF document text
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/26419313792.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160996c47685fa---55833455819.pdfIn PDF document text
    • https://k-newsletter.com/ckupload/files/86691948091.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/tinofekitu.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/to6ipriu08o92aheieen87kbdh/33655084962.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/51527585127.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abbf2cb6d37---tipulukaserefowevakeb.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/aca39b282ff30a7520a5d847ac44b225/patirovipinebavirisik.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/110c6f71699926a431d721d7da7159c6/rojazunivetibenosisofi.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/307d84144c9e10b446da6f13a6646988/51325160805.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/fapededu.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bde2e9774a9---75724883850.pdfIn PDF document text
    • https://serka.com/serka/upload/files/zosenulupozazikisub.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/71800941307.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/jipoguf.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/lstm6202kv90ars3n7c1va27t4/55765029499.pdfIn PDF document text
    • https://solturism.ro/images/file/96803344843.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/vobugolug.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160918c6f55d1a---muxoranus.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/29040946970.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/fevavixadujulozekunugapis.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609843894862b---dawiluzitewasapipa.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_off0000d103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD103 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e91a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91A 10984 bytes
SHA-256: f6a5f7ebf96d3232496674f83169a0279b984d46911d61c51cdf788e5051cdcd
font_02_sfnt_off00010267.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10267 17840 bytes
SHA-256: 024399b23d4dbf0e482d33b74ade5b23a01ca13d2f0ff9ce1142fbe243fbb5b0