Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf1bbbd84eddc0ef…

MALICIOUS

PDF

84.6 KB Created: 2021-06-27 17:09:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ff05f27fb3feff52d30e61172eae43cd SHA-1: 96d613e08cf52160cf62b0866ead00cd2421531b SHA-256: cf1bbbd84eddc0ef35439c2001675fbb9db83086e0970012333f300dc2ab80b7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains numerous links pointing to compromised WordPress sites, likely intended to host malicious documents. The ClamAV detection and ML classifier strongly indicate malicious intent, with the links suggesting a phishing or malware distribution campaign. No scripts were extracted, but the PDF structure and embedded URLs are indicative of a malicious document dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/e9957f90c5c47afffe7c541563a1d8da/sorerojimadosuvi.pdf In PDF document text
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/f3d9b31e471bc147ef0cd186560c17ff/7152136382.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad0a5dd871f---32027237790.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/7cma4aj1tmd26kcd9lnmbtau50/kezuligalumoveka.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c41171c2bba---kuzovogiperu.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b49098356b8---sililidefe.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/mesujovemofijetijabiliwa.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/ramujal.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c84c630e4b9---mebanogimividek.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/59e1017e500daae607a4682dfc96923b/37880752539.pdfIn PDF document text
    • https://mangmalungtea.com/userfiles/file/640842769.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160882b3209587---66187842116.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/33417364086.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/dc7cffcea3b71310a49384fe193e4881/23922410434.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0269b9b51---sivifilofikebabufebi.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/366f2704e367b7f99ac840c9a7df7504/90579125585.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/mbpa64n5qlj7elcsin6pmo3c27/sebakedidisazikarezaxulaf.pdfIn PDF document text
    • http://jngf.cn/files/file/sanusar.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/18123044683.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/5e451158e9b1de788a603e588002c001/11549555565.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/58130919880.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/ee56fd2f36f714af721e4bcf95398da5/xazanebawodi.pdfIn PDF document text
    • http://bogieclassof67.com/clients/71235/File/54557283250.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/wuropux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=electronic+configuration+of+all+elements+pdf+downloadPDF 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_off0000e7b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B6 11132 bytes
SHA-256: 74dc30545fc968dbaa896dc4a1ebd11d87e38b5af58f0e40021e205c6e89b5b5
font_01_sfnt_off00010189.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10189 16552 bytes
SHA-256: fd85830bf4b0711d4ae7af0c706f46084c5439868b9e83bfcd01d16a67889e50
font_02_sfnt_off00012ca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1