Malicious PDF — malware analysis report

Static analysis result for SHA-256 a42b20ed84f0e956…

MALICIOUS

PDF

84.9 KB Created: 2021-09-06 02:11:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6101a1b3f97ddcb3de9bb3be77ef446b SHA-1: bda7974ca16b79e7b22445c41538e8237af54cb3 SHA-256: a42b20ed84f0e95687d3b216af0d9614e2b19cebb09874ba9a0700a24a3f2c3d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's designed to redirect users to malicious sites. The embedded URLs, such as http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/01f0a9c5daff7ed237322f6edfc96937/kovujozamozemikoful.pdf, are key indicators of this redirection behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bebe4e00cdf---30624190312.pdf In PDF document text
    • https://baongochoa.com/upload/file/zixosesujuvajejalasunax.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/01f0a9c5daff7ed237322f6edfc96937/kovujozamozemikoful.pdfIn PDF document text
    • http://nhatngungoisaoxanh.com/upload/files/jixote.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/funukevajefosazetejag.pdfIn PDF document text
    • http://sibservis.com/ckfinder/userfiles/files/60540910540.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/73ac83e55cf7649486cbaa8a6f638a1e/duliwopepagusedurameweg.pdfIn PDF document text
    • http://wittzumstegfamilyreunion.com/clients/e/e5/e56c03c63d8c9260b12fda9e5e6a3df6/File/jowasuvuzadivelof.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/92074559367.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/vowefefemapugutavalijivo.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-3/20210503141911995396.pdfIn PDF document text
    • http://fontanarosaserigrafia.it/userfiles/file/pojipo.pdfIn PDF document text
    • http://tolaniprojects.com/userfiles/file/zesananofasikez.pdfIn PDF document text
    • http://hcvitamin.com/webroot/img/files/bopere.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b9862bd2bc4---73543078085.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/butevud.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/ppuv9a2m8i2vcmlb9qf9ckg3mv/20709331119.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c44a23034e1---85389546527.pdfIn PDF document text
    • http://icbiz.ru/userfiles/file/zekumoxifiwelovowofedewuv.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/ucnl3snbjq6cng88ar7uo74i9t/89953755082.pdfIn PDF document text
    • http://mariamozharova.ru/uploads/files/zejinidurovifemebexowod.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16088b8f3f1b16---bilazimafitaz.pdfIn PDF document text
    • https://icoachyou.biz/images/ckeditor/files/majebub.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/0dolupdepo6hmkfd4q6cmm045q/84902934681.pdfIn PDF document text
    • http://blevy.com/ckfinder/userfiles/files/13768572327.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=recetario+saludable+para+comedores+comunitarios+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_off0000e121.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE121 20048 bytes
SHA-256: ff1e719853d428d888ffbf1d45bcc5ca3406b2f3647411a0a5183f694396d047
font_01_sfnt_off00011357.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11357 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012b6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B6E 11064 bytes
SHA-256: 6224583fa3ee82c5f780b067192d69d7a746b6447cf802402eba35963022a5ae