Malicious PDF — malware analysis report

Static analysis result for SHA-256 235812724c6dbacf…

MALICIOUS

PDF

73.0 KB Created: 2021-09-06 14:53:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ba7250608a1512df19441d2614dd92df SHA-1: a941fac115ca3e52ed2ac8bbc801793cdc4899a9 SHA-256: 235812724c6dbacf3709ad4c0b5f7c9eef83b557c65814555e2c46e8708e062b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage and other potentially malicious PDF files. The presence of embedded URLs and the nature of the heuristics suggest an attempt to trick users into downloading further malware, likely through a phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c6461edac5---6444827336.pdf In PDF document text
    • https://balticstroy.com/uploads/files/25529922342.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1612ca6618d6d5---81160381849.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/zudavusuganofademosow.pdfIn PDF document text
    • http://akvari-um.ru/userfiles/file/rutekejodes.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a30ea3999---toxobeselikivazufuvebe.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/64911243245.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160831ee9cab7f---movuxiriked.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/19955291269.pdfIn PDF document text
    • http://gldbirdgel.com/user_img/files/xetorojomaxazibukex.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/29646823082.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985bf389fd4---nesabuzudelamiku.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1c446ed9d---64374212984.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c560f9df5ea---21076012896.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/37967209978.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210601_89E65658C9541B90.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/e7963b3221916fed1c7571cabf52090b/datadavarogibogevetof.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160743ec6bcc54---99541220641.pdfIn PDF document text
    • https://airbays.com/userfiles/file/61853275692.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/gt3ckdoeol5n6800j2e3pdgn78/84644091757.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/70115995135.pdfIn PDF document text
    • http://cauthangdep24h.com/upload/files/92124544133.pdfIn PDF document text
    • http://esistore.be/userfiles/file/12041607788.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/811c1bc6b59319918a405b715322b673/lovovakazokif.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b230c59801---wenomonoxolovawekoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=honda+civic+2015+owners+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_off0000bb1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB1A 11104 bytes
SHA-256: 2defbe8f1e80a0229f65f02328f560da1eb2a04af0ffc2f9c8f1fe269d1887b9
font_01_sfnt_off0000d51d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD51D 16000 bytes
SHA-256: 34f005ac7442a27f619d08a15d20344db3f048a3ce98fc72c1951f20b4171f90
font_02_sfnt_off0000fe44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1