Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdb396c723f5b395…

MALICIOUS

PDF

88.6 KB Created: 2021-09-02 14:16:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a48c1e93548914c000d3b123eabe0346 SHA-1: 1b824e1f3b5d5309f576f31545af60035170625b SHA-256: cdb396c723f5b3955455cf1cdf01c85c5d9289af5d4e659c21e54c2f17f67d51
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This suggests a multi-stage attack, likely for phishing or malware distribution, where the initial PDF acts as a lure to download further malicious content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c98f2249bcf---bopepinutujidujiduxatu.pdf In PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e93b5bb67---tosederodupaboxurolowuxa.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/92668647898.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/jekunaruke.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/tiwujidufax.pdfIn PDF document text
    • http://generaldistco.com/images/file/dujivoj.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/zonegu.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/9808570117.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/t32t882c709mvmg71psc6rt419/kawopazes.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a382cdbe0cb---22249843753.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160777b39d45c5---29447167540.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/56584626219.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/63108208844.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f98d9f73e---budozox.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/83530180268.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/e2084191d8b31c57b082f35b9f03a593/paputibofutigetelari.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608a02fdeea5f---76717182668.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/bokav.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607924b040a90---vexarimuvifiwuvi.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e7a85f662---nekuvubugusakoxunagom.pdfIn PDF document text
    • http://www.patriarca-batiment.com/ressource/site-image/files/wirugazekojasixejalow.pdfIn PDF document text
    • http://stickerbarcode.com/file_media/file_image/file/mafawekagusuveko.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16079b98514e34---jawitilufonifoselasuzebu.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/semorakovuxosevivi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=nissan+sunny+b13+service+manualPDF 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_off0000efe2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE2 20036 bytes
SHA-256: 58aabdf1daf54871b893b5dfbc42c88da77ed1daadc25428d566ea71b63a3c28
font_01_sfnt_off00012358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12358 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013b6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B6F 10796 bytes
SHA-256: 938be3a9ce653b8fd06fc85a68fefde2d7eb3b26e8286a52d00ae9e0130de135