Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a15a3dc4091a152…

MALICIOUS

PDF

78.0 KB Created: 2021-07-16 20:42:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: aea0e207a8963c15047197455b52ad5d SHA-1: a27f6c935a6c2d9f62a883bd90a32ca4ac252000 SHA-256: 8a15a3dc4091a15228a894f933b34c2fe704e71ff0aa72784f111cf9aab684b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues about its specific purpose beyond the presence of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1608156c1c1169---75971983314.pdf In PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4c8201170---zujizezi.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/338adf40b14342c3d1aa6c5ed5457e29/39047831831.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/43168100531.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/48620d5959da9c808d6cb7b6282b54ec/begovakimulesuxeruletima.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160784e752c2cb---texemog.pdfIn PDF document text
    • https://altbuket.ru/files/gofugobewemi.pdfIn PDF document text
    • https://digireg.cz/upload/pajuxin.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5df16318b---tuxadimoki.pdfIn PDF document text
    • http://quocteanviet.com/img-chamthi/files/94318493534.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/bc6c55144fb02a0fa710cfcb8298d6d4/vagakosilesasewapaganugi.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd2af78c15---28715899126.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085548751cc5---65568118222.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/67975492290.pdfIn PDF document text
    • http://berbun.com/user_img/file/91688949479.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210515/file/wewulitagorikoga.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f27af42a1e---totumik.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa58297cf4f---gamadanumufifivasinel.pdfIn PDF document text
    • http://aiskreunion.com/clients/b/b4/b417c2091670ce0b0d78f4b231aea02c/File/dukonogojugofexakogefe.pdfIn PDF document text
    • https://codecs.roimages/file/26561928475.pdfIn PDF document text
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/voeppnfnn5fv3q26eebt1djk5v/8245748580.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0342c79bc---54956419463.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/vujeperavabalulexebemu.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/oh0dsqcad0v6ik0g9cmoq3crop/zunaxuvixurofid.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210626013011.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=engineering+chemistry+by+ramadevi+pdfPDF 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_off0000d1f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F3 15272 bytes
SHA-256: f445ca5a080d376c8f3bb6273c1d43d7fbc250ee2912e2f26005f8fe893a2b98
font_01_sfnt_off0000f8e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110F9 11204 bytes
SHA-256: 257cee547e179e49aed7d00937f42b26b07bcd555b572f332687037c650daa38