Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d9d789e88db9e7a…

MALICIOUS

PDF

69.5 KB Created: 2021-10-01 05:37:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6bf7b8c7b1f235f92ace3620c692adb4 SHA-1: 5564c047a26659a945961e96e09d55963f65df3d SHA-256: 4d9d789e88db9e7ac7976c9fe47e34a99c565fb90f8992e5fc84bc35327046ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is 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 multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous PDF links suggests an attempt to obscure the true destination or distribute phishing content.

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://e-ceramika.pl/userfiles/file/midupagatu.pdf In PDF document text
    • https://ginniglobal.com/uploads/file/gozafitari.pdfIn PDF document text
    • http://hnfhdc.com/UpLoadFile/2021092515145046141.pdfIn PDF document text
    • https://matricula.arendic.cl/files/6669261883.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/tapukan.pdfIn PDF document text
    • http://fd-health.com/upload/ckeditor/files/nerixifegujajo.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/84616772538.pdfIn PDF document text
    • http://ed-union05.ru/files/file/gufagu.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/fetew.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/xilulukuzefudipofodofufev.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-29/20210929145430897185.pdfIn PDF document text
    • http://origo.ws/userfiles/file/pimimejitewi.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/93247625896.pdfIn PDF document text
    • https://trade.inter-ural.ru/ckfinder/userfiles/files/47122354808.pdfIn PDF document text
    • http://ateliergermain.org/sites/default/files/file/3515125326.pdfIn PDF document text
    • https://mytshirtcreator.com/app/webroot/files/file/29370649741.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/sulojewusenijomoli.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16130307f497ac---resepajosaxamasaripun.pdfIn PDF document text
    • http://fotografiafrancescosomma.com/userfiles/files/doxetadobadurolagewusel.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/ef77a98ec21846f90a2642800a2b2547/kisobajipowib.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/a81aed585ce91bd6ce7217faab8a941c/gogasofaket.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/tiditubefedo.pdfIn PDF document text
    • http://camelliafb.com/uploads/files/202109271527037706.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/57513469575.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=minecraft+in+browserPDF link annotation
    • http://crossfit28.com.s125853.gridserver.com/siteuploads/editorimg/file/vatiwuxutarizaf.pdfIn 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://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_off0000b0f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0F2 15884 bytes
SHA-256: 9b5985b402d6184d7df3037240411c40aafa1b600c8ee4dc8668f618e0bd4f75
font_01_sfnt_off0000d8c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DC 10500 bytes
SHA-256: 32ed736fa18ab8cbe12926c534dcda19f770cde0b74d50538b1eb465b5d38067