Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c4bd467c3dbfc6…

MALICIOUS

PDF

83.6 KB Created: 2021-07-03 00:35:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a6746c511d8c292546ff38e18bd80612 SHA-1: 52c25c42975d941987347dd423c576a00d7f14e3 SHA-256: 51c4bd467c3dbfc6c84f40090ea2f4d38ce7eaf2a8d4e9bb5029d56b88f07e70
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised CMS upload storage, and exhibits characteristics of a link farm designed for SEO manipulation. The heuristic 'SE_INVOICE_LURE' suggests the document's content is intended to mimic an invoice or payment notification, encouraging user interaction with the embedded links. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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 http://www.alexgis.com/siteuploads/editorimg/file/76178901049.pdf In PDF document text
    • https://bobecoingatlan.com/uploads/editor/file/xilesekoza.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/0f3e1501e54200b3c3c33c7e01f4e2fa/wilusisopuxexebireg.pdfIn PDF document text
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/48102112937.pdfIn PDF document text
    • https://f27szerviz.hu/upload/files/bebopadanefan.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40acf51310---tefeb.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb9c70380c---zaviparufofusotidir.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/41034857440.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160bae51c176bb---xupunopi.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///33684100501.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/heaum82d5mjnujfskeuotf6m9i/foxizonubijofekez.pdfIn PDF document text
    • http://proxima-design.cz/files/file/wurefijemixe.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/70010294032.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7ed390fc1---wanoxozuzedijafadulimag.pdfIn PDF document text
    • https://puppometalli.eu/file/vuzebo.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/ebu459euj2b5efa3e5dnnq03o0/70730441182.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/86704376199.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/7370989cb36f5b73efffdb049549f6a4/piwuk.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0e89aeebfb1f03e9b1b7ec115714ae09/64373588600.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/c23c63fcf3a972bfa2bf4f61a3318773/wiwisadibepisovixi.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c26672f17---33624831716.pdfIn PDF document text
    • http://facilitymanagementassociates.com/survey/userfiles/files/bezurenapotifux.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a299ff618f9---ribobovatorolexulavifoji.pdfIn PDF document text
    • http://wagnerpc.com/userfiles/files/71844210257.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=this+is+to+acknowledge+the+receipt+of+paymentPDF 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_off0000e38a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38A 11324 bytes
SHA-256: 7ae33de8631b76d4f305fccf035a5059ccff66f1e600cfa5af9e7fa771eee1b7
font_01_sfnt_off0000fde5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115F7 16508 bytes
SHA-256: 512b0fea09784c1a9cf848d4a4e1d659a7c7c9c54b725ca713695d2518930f6b