Malicious PDF — malware analysis report

Static analysis result for SHA-256 998f4b8d83787973…

MALICIOUS

PDF

90.9 KB Created: 2021-09-05 11:49:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bef367342c2595d39b7123ff6347a94f SHA-1: c75393b8c351b121535081b8e3a30f5278178d00 SHA-256: 998f4b8d837879733c20aec63ca658475b4e62bddbe1417954f9183a82efb2f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute phishing content or further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate effort to obscure the true destination through a large number of distinct hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160de57ff1d23c---wezogejelevo.pdf In PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/82eb05e0a1fbfd646940ac4ca81633c2/3898259180.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/5d63a48efb3e75e5f47a3ed79cac3730/59450518336.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/37447299469.pdfIn PDF document text
    • http://klaaswester.nl/img/file/2515805733.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/a2c3075cccf14ed7b72d2db39e47a99c/55726140338.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160b84ce859e81---miwunozij.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/wubizerogage.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/gamalaj.pdfIn PDF document text
    • http://ankaraeksioglu.com/resimler/files/36563942656.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609badcfce852---kakevabasisivapumizunas.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/pewezatepilibozopejaliv.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/66939620604.pdfIn PDF document text
    • http://bjbtrh.com/files/pic/file/xajanipiferalojetev.pdfIn PDF document text
    • http://igabana.com/upfolder/e/files/20210821025606.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/herpadue6ss4ke1pe8oj2g7uhh/2121946437.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160fb7e00b0dce---4924884756.pdfIn PDF document text
    • http://doradcyprawni.com/images/pliki/zosavuvafavidofa.pdfIn PDF document text
    • http://darec.sk/files/files/kuvopefem.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021710145946.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/580a959acb1cd9042b06227a80a0b9b6/jopemeri.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160d25267ed47e---12992729334.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/8323ca18952c55adfb1bf5d1437121a0/kikuzarimukaxitul.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/5539955127.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/a1acc51a1870a311bc71745b33a13cea/sugegefunezaleguxewuwava.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/vuwupolo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=benefits+of+climate+smart+agriculture+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_off0000fa27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA27 11116 bytes
SHA-256: ffe6dc30e9a0aa36fc2613684e75296098eca56fc9e73bd2617c12047c46b816
font_01_sfnt_off000113ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012bfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BFE 19168 bytes
SHA-256: 20cf0ed3b74d451205b433caf84fed7610a5e97d2086534156966a6afe8cc2a0