Malicious PDF — malware analysis report

Static analysis result for SHA-256 445391673322217d…

MALICIOUS

PDF

77.3 KB Created: 2021-09-26 23:22:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: cfc0ff1de128b51bfdcc05532dc15891 SHA-1: 46cdce9e8a241c38ab1091493d9046eff64c387f SHA-256: 445391673322217d40e9d41a90d463a50a07d7b38e618071b1412b28778f461d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is designed as a link farm, pointing to numerous suspicious URLs, many of which are hosted on disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://laborke.ru/uplcv?utm_term=how+to+access+a+phone+with+broken+screen PDF link annotation
    • http://kowel.com/ckfinder/userfiles/files/1631190231.pdfIn PDF document text
    • https://anbuadidravidarmatrimony.com/ckfinder/userfiles/files/vulevobuzawisuzijad.pdfIn PDF document text
    • http://nollve.com/img/editor/image/file/bumevin.pdfIn PDF document text
    • http://spadhotel.com/basefile/spadhotelcom/files/zerubegoxu.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/99934990286.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/76940338568841fa845bc225ab86d460/82340129177.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/62164851526.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/59157328158.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/togobun.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210909202012.pdfIn PDF document text
    • https://ripedzn.com/app/webroot/files/fckeditor/file/sazeweribolagigitoju.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/8899623493.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/bivubadobedawunasiziga.pdfIn PDF document text
    • https://ms02bet.net/contents/files/puromizizumakulokeduj.pdfIn PDF document text
    • https://vieclamlaocai.vn/webroot/img/files/kutafobadusinuzugewumagun.pdfIn PDF document text
    • http://toyotaprius-custom.com/js/upload/files/fomilulebutepaba.pdfIn PDF document text
    • https://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/32003091560.pdfIn PDF document text
    • http://mitsubishilongbien.vn/images/ckeditor/files/xigakuwe.pdfIn PDF document text
    • https://theipbuzz.com/images/file/83803825517.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/tamoxakokixit.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/xovelodediwitelonig.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf1530b651---turefar.pdfIn PDF document text
    • http://huucodatlanh.com/userfiles/file/46018941272.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/pezonotesewodikiro.pdfIn PDF document text
    • https://1tlstar.com/storage/uploads/files/35025416932.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_off0000c2e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2E0 20248 bytes
SHA-256: 265c95928576b1a0d0390be86b0990e7d15def507134c7540bb804a5ca9bb2f4
font_01_sfnt_off0000f744.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF744 10732 bytes
SHA-256: f7753e1ee8371d8d83e5a8b51291cf8bd9af04682874d4c909683a10fc6b9e1c
font_02_sfnt_off00010fb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1