Malicious PDF — malware analysis report

Static analysis result for SHA-256 81cf09beb318a04d…

MALICIOUS

PDF

80.0 KB Created: 2021-09-18 07:58:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a485bddb369f0d1b062a6a5e07b38936 SHA-1: 5e2b764de7c89d5671b4916be4c065f751dc83bc SHA-256: 81cf09beb318a04dc87db10d87967d3d7a1b56d95ee1a40e604d8a9a5c89d13d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external links suggests an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://metabolitplus.ru/files/file/53166565101.pdf In PDF document text
    • http://augustaelectricalwork.com/editorData/file/93369978006.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16145147b24af6---29233121761.pdfIn PDF document text
    • https://trickapotisk.cz/webpagebuilder/ckfinder/userfiles/files/25415691146.pdfIn PDF document text
    • http://vitrine-prof.com/files/sakep.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/e52dc4c64bf1ea43b9780c1dbcbe93e1/2675604227.pdfIn PDF document text
    • http://cnsgafgl.netsociality.com/upload/files/duresavirejizi.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/fupilefewazadedirevofilun.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109041046284469.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/57714292898.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109061632337035.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/xuzej.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a771697aa---zeneb.pdfIn PDF document text
    • http://perksys.com/userfiles/file/melekifumadazixizamure.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210913043525455457.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/59851916850.pdfIn PDF document text
    • https://minipowerpack.net/upload/files/zerutuzuzuvupusaz.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/loduribokusuluwomevunub.pdfIn PDF document text
    • http://fishngrill.iorderfoods.com/uploads/files/busimijonozonawovi.pdfIn PDF document text
    • http://xn----ftbkdcamitb5h.xn--p1acf/files/fck/file/38807469201.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613740f7407f7---69609134558.pdfIn PDF document text
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/1624700825.pdfIn PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/10126473888.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=online+among+us+onlinePDF 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_off0000d792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD792 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA4 16852 bytes
SHA-256: 1c45a0b4a56de1fbdc1b3fc810ccdcb9c4ea98b2128d03b344ac73efe34dc61c
font_02_sfnt_off00011b0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B0C 10376 bytes
SHA-256: 6c998ec4c79c5a4812541c980c5370c181268a54b649607307355048a843f8cb