Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85f4367173b0c32…

MALICIOUS

PDF

70.9 KB Created: 2021-06-25 23:01:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7af65cc87e559bb22d1185b2e7c13510 SHA-1: 00014922740b4ff7303f57ed4cb2b01716fbc105 SHA-256: a85f4367173b0c329cac88c2e33758cf48437e04d9a965a092a0475eb30b49ae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable domains, indicating a link farm designed to lure users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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 http://comlark.ru/userfiles/files/pevoluvizefonabudop.pdf In PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082236573540---gepiwederimakedifav.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/56eab816ffe7499a519e372dd15f6acd/zivogobokatenufuloj.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/bb71d814a20d72c1ef4c21ab4cca436c/4793389713.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098357601b74---24711466308.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/notazorumorumavitufuful.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/06ac745a86348085d711acd50addd412/zasuwefival.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a017b87de85---99629054570.pdfIn PDF document text
    • http://sashtraayurveda.com/ckfinder/userfiles/files/dopulizit.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c9d5f40b245---nezetegajome.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/ea2410cfb1e0cd94bfdb44e05a86a088/birinefugorawusixesumu.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a98576bcfb5---23197474047.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e72f1f6cd22824f5240bac14319b0a7c/88314490547.pdfIn PDF document text
    • http://brucemsmithlaw.com/clients/e/e2/e252bfde01ef004f685a9648d307a4b9/File/koluwoxov.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d7189140e---6659034472.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/54804569643.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/2tjd5bsp049qbp8g4o341glu54/53183442755.pdfIn PDF document text
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/8124248513.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/ede3af5c1ec09a4a110243d719c8b503/ruzulu.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608e04c326f7e---99713973172.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160c0c432b7a60---90995804144.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b34ee7cd308---xozatotik.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c411965d55d---30424474482.pdfIn PDF document text
    • http://klhl.com/userfiles/file/83683042660.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a92e550c3ea---zezozaxafepizadevo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=acids+and+bases+test+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_off0000b5ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5CA 10468 bytes
SHA-256: ffc4620ea2eb2e84c3632d3060ffb09faef3af39df7358dfff085271bccd86c8
font_01_sfnt_off0000cd7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7E 15348 bytes
SHA-256: b41baab84b052afb03899aafd91cd5fa09b391c7fe0d42e95316af1f5a5612ab
font_02_sfnt_off0000f4e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1