Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa3407a297d91c50…

MALICIOUS

PDF

81.5 KB Created: 2021-08-28 13:01:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 19ed8feaf735f56f98e9bfa85b0c399b SHA-1: 2e66184926b912f5937a4fbca961d02f9e56eba0 SHA-256: aa3407a297d91c503055188dfdc3abf1205078f48d4d465d39735f5bca0fd1ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or SEO manipulation scheme. Although no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript for redirection or obfuscation, hence T1059.007 is included.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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://gonguyenkhoi.vn/upload/files/32208320093.pdf In PDF document text
    • http://vizugy.hu/uploads/files/9472180296.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/kerewarewipekoka.pdfIn PDF document text
    • https://www.nickelmarket.co.za/includes/ckfinder/userfiles/files/tukunebuzewim.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/podonagorusonozoxog.pdfIn PDF document text
    • http://arcadia-fitness.es/userfiles/file/pozugafasokasareruxawev.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/5vtok65glgb8u7pfv8prkdjqd3/16427337266.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/db51bc6ce57425248498f1d2fa9f6064/kaxanuli.pdfIn PDF document text
    • http://rowsontw.com/shopadmin/upload/files/86397235401.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/59005637154.pdfIn PDF document text
    • https://anglarill.net/userfiles/file/31638767754.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/lufinunaxarovajulijeda.pdfIn PDF document text
    • https://digireg.cz/upload/fulavi.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070191da7fda---zelakozi.pdfIn PDF document text
    • http://livingkaneohe.com/userimages/xisukesewizizikimapux.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160758b3306f6a---49857103239.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d0c2bec61ff---sigamed.pdfIn PDF document text
    • http://myboydfamily.com/clients/7/7f/7f513a2250c12de81a70a6735749c289/File/fipimivafev.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/61516951230.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607046aa457e2---fekik.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa//files/puparinexezitema.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c68e98dd7---zawuponabeteka.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/ogkoqru9bk0pjdiv1d73hmqqan/tubopasikixenuw.pdfIn PDF document text
    • https://ytdrive.com/CKEdit/upload/files/72633768937.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/96650218218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+to+change+size+of+a+pdf+documentPDF 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_off0000d98c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD98C 16804 bytes
SHA-256: 4b46dd3f844b51b118696f44e017bea93aadc0aebd2ee4bf89dc55129da03f90
font_01_sfnt_off000104e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E0 11160 bytes
SHA-256: 0fec2c8e3b2332592bb0a8a49839f984b01e4ed0991b2c7318ef484601c755d5
font_02_sfnt_off00011eab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1