Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e72ea7d5825d96…

MALICIOUS

PDF

75.8 KB Created: 2021-09-15 17:58:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2444a1f88d558b381145673b9818c67b SHA-1: dc521c5e4560c8a11b747bf454df765a8dda18d0 SHA-256: 81e72ea7d5825d96a7a727f09ef2fb7fda4eaf75f907c06cea1ae572d4451c2b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or malware distribution attempt. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farms strongly suggests an attempt to lead the user to a malicious site, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://drafthe.ru/uplcv?utm_term=android+phone+flashing+software+free+download+for+pc PDF link annotation
    • https://stotex.rs/files/runedapimib.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/rufefe.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/161382918485e4---90614232672.pdfIn PDF document text
    • https://haidangpc.com/contents/files/9151895684.pdfIn PDF document text
    • http://milkexim.ru/imgeditor/file/gopelidejulilimo.pdfIn PDF document text
    • http://turystyka.powiatlubartowski.pl/admin/ckfinder/userfiles/files/widuvafusikukokebefebe.pdfIn PDF document text
    • http://wohingltd.com/userfiles/tazadegarafod.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e25baabddf---samuxavadekaxuremaxumat.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/bezalu.pdfIn PDF document text
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/75739454203.pdfIn PDF document text
    • https://aneri12.cz/res/file/borinojepojidonan.pdfIn PDF document text
    • https://nepalipublisher.com/ckfinder/userfiles/files/56930225453.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/5e1b3a149859b93de51ddf629873154e/98525175011.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/sagakedaxopisi.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/d279b542ef1927f8f451749268271c42/81903831542.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/32157742625.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/9865055991.pdfIn PDF document text
    • http://www.polni.si/Images/files/pijijodaxegimesatumanigab.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/xidusa.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-12/20210912223300799064.pdfIn PDF document text
    • http://abwferrellpkwy.com/uploads/files/61089091076.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161352283b5714---10626756848.pdfIn PDF document text
    • http://agroanaliz.by/upload/editor/files/80736422344.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_off0000c476.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC476 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC88 16972 bytes
SHA-256: 2c8cfda02464caecf7e78ab7f50aebe10b8162c270692c13cd2579e0b53e2138
font_02_sfnt_off00010817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10817 10964 bytes
SHA-256: 108a76c3a65e8c5fe172557da224cd05b20b282f1a70391ed4705f34acf2704c