Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4a3f77952808028…

MALICIOUS

PDF

71.7 KB Created: 2021-06-07 17:56:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 13c47c7263449efc4e500ee22ff20867 SHA-1: f98dd79784afdaf1006fd76b0c1ffbf58a113350 SHA-256: a4a3f7795280802802b0010abb1abf08a5c233e4b5931ef90a705eff98122790
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was detected 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 compromised WordPress sites and disposable hosting, likely serving as a lure for phishing or malware downloads. While no scripts were explicitly extracted, the PDF structure itself facilitates the redirection, aligning with techniques used for initial access via malicious attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://laborke.ru/uplcv?utm_term=what+is+gmp+compliance PDF link annotation
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2cd505757---52560503378.pdfIn PDF document text
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/bb1d3a93f8ce3114c4a6c47630f94aa6/78395168536.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/13a7319b7fc23e19346f6b6e3fc10ba0/74113102294.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af6a35f11d5---40707578733.pdfIn PDF document text
    • http://gagutp.com/sa_upload/userfiles/file/20210514081616.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/kiei00acjdbhjgv14al7le0h07/pixinozamadelabuwiraden.pdfIn PDF document text
    • http://ithaca1966.com/clients/8/85/85e9e0a76fddb83d7689cebc6ab07fae/File/dozavowepajekami.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/funarosewevami.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5a6971e4d8---91557878860.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/527c14c4bda85ad6162ce32ae24b405a/konilifuzizubesabanaz.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/985b9cf42be01056bdcd740af3f2023e/topawamufezunodudemiteto.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/ba6bb8457c95bb263fbc041ce42bf6f4/fatobusawudipaju.pdfIn PDF document text
    • http://biosurfest.com/userfiles/files/nojogigomanojonivuxod.pdfIn PDF document text
    • http://lhs60to70.com/clients/3/32/32806278e47d7e4d905c37b1d6ebf04a/File/barefudimip.pdfIn PDF document text
    • https://suprizpin.com/calisma2/files/uploads/bovenutegodipo.pdfIn PDF document text
    • https://misionesmedellin2030.com/wp-content/plugins/super-forms/uploads/php/files/5lgtoc8a60edaecghv7pe3dv9c/11767962392.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a57254bf1a2---futoz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC79 5264 bytes
SHA-256: 1b9960eb1075ec9cddb6f8c74e567a4b3ead5e482a2df09f5df75d7257d94d0d
font_01_sfnt_off0000ee50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE50 10416 bytes
SHA-256: 5ee71bbdfbb67f8af265fcbf8c9b88a4f772e8dc0f1b1e2cdf065c96fb2d472d