Malicious PDF — malware analysis report

Static analysis result for SHA-256 adc837cbb85226ea…

MALICIOUS

PDF

82.9 KB Created: 2021-09-13 22:36:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 27ff53bfe09de1551452a3f15030fdf7 SHA-1: 55025addb6629da28abd640f3b01549fc2a24f0a SHA-256: adc837cbb85226ea61034d5e7cd2a24da7cb6b528259ee93e424003038027cf7
142 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URIs, including one identified as a link farm on disposable hosting, suggests the PDF is designed to exploit vulnerabilities or trick users into downloading further malicious content. The 'SE_DOWNLOAD_BUTTON' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/wajirogidodosatowusuj.pdf In PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613747e594059---rexevidugixoponobuxotegut.pdfIn PDF document text
    • http://betheaskssd.com/flash/betheaskssd.com/file/wokaluvowajep.pdfIn PDF document text
    • http://amidoux-peintures.com/ckfinder/userfiles/files/zubaxavulabu.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/3687107241.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/mevasuwesupibezewotebama.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/89679457727.pdfIn PDF document text
    • http://mwcapital.net/ckfinder/userfiles/files/25414910715.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/digiruxetuxogasep.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320e248604e---ralalapikobonilajetes.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/12755671556.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/89906389927.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/gokupufosanobabe.pdfIn PDF document text
    • http://www.videocopilot.net/assets/public/ckfinder/userfiles/files/tetamazokana.pdfIn PDF document text
    • https://powermailer.in/userfiles/file/28282848787.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/71504357279.pdfIn PDF document text
    • https://anukulagrotech.com/ci/userfiles/files/muligotelufur.pdfIn PDF document text
    • https://premiersuli.hu/files/files/tifamojolanorojikusumubiv.pdfIn PDF document text
    • http://amandatour.ru/js/ckfinder/userfiles/files/88041283649.pdfIn PDF document text
    • https://pasarant0g3l-turbo-h1t.com/contents/files/xujewuran.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/tesovuwitadino.pdfIn PDF document text
    • http://testsitehq.com/ckeditor-ckfinder-integration/uploads/files/91570198254.pdfIn PDF document text
    • http://ilkyoukais.com/Images/Media/files/lujenopa.pdfIn PDF document text
    • https://easy2ticket.com/upload/files/pulatomupipapudelozikijid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=clash+royale+unlimited+elixir+modPDF 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_off0000dca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA4 10860 bytes
SHA-256: bd00c8ca6c7c2c62819d07086f5df9e0bad7b42d7465e9c7f540eadca554d144
font_01_sfnt_off0000f58c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58C 18436 bytes
SHA-256: 8d5f2b26eddb4873742ae576c3ed3c185cfd12683c26476ae196714a4c2d7e76
font_02_sfnt_off0001257c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1257C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1