Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8a87584756eef10…

MALICIOUS

PDF

76.0 KB Created: 2021-06-28 16:15:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 086ece45f215a23468bd1488e5e031a1 SHA-1: d1328f301845d99fb076bfbfeaff06c0a21dc83c SHA-256: a8a87584756eef10c58180294cebd51c5496391f21958853cc6eae6878a4ddbf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to external sites, some hosted on compromised WordPress installations. This pattern suggests the PDF is used to redirect users to phishing pages or sites hosting further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://inwebjor.ru/uplcv?utm_term=biology+chapter+5+review+answer+key PDF link annotation
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/i1em58rurii9tmt2valt3bojsi/sanuzonovemogujuv.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/pdtcheq2m19u3tqjn5h3ht5tlq/bufuvunosesili.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/e5fcl7irdobemkqqp48bm8e5j7/66348063546.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/su28n0jg73kt57ka8gfec0rq27/86477273427.pdfIn PDF document text
    • http://sgadsahodayatarntaran.org/sahodyatarntarannew/userfiles/file/27668870738.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/63576233836.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/950ad0c9689c632d10fcd9d350ab758a/41764954754.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/vodimu.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4ccd990fa---60415019202.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a533b664f6b---jeduf.pdfIn PDF document text
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/33be757fb05af82e66bcf2d2398850d1/1437499935.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160820ff93b2c4---73970384878.pdfIn PDF document text
    • http://altinay-law.com/images/file/63314952143.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/6e4641040e15f9b38b28cd522bfd7d32/jedibefo.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607d471f672c4---73234412057.pdfIn PDF document text
    • http://alkanboya.com/files/file///turuvi.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609764e051c66---45118853207.pdfIn PDF document text
    • http://grodgolf.com/clients/f/fd/fd83fa7079552abb47853a85229f74c1/File/79399938423.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/vamitazogixiramutopow.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a9f517109e---jejugumokonawagivajuliva.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///15456127515.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a609a1e0da4---94980477769.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/99110877823.pdfIn PDF document text
    • http://dancedynamicsla.com/clients/38740/File/94588291594.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/gl35h6ovmv052f81tc22svluag/78702229471.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/0b1de10842bfa5675f571d03edb8ba98/69080958919.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_off0000c6f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6F6 11196 bytes
SHA-256: 4b519c98a05fc1934dd791a2467081fa9de8653585284d89d2e0db1e0c6b1a5e
font_01_sfnt_off0000e155.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE155 15912 bytes
SHA-256: 649a8da87f5d03c387dc8b6d5a998d9c6ff41927618cfa98262e551bfa93fe41
font_02_sfnt_off00010a55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A55 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1