Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8908a1bbab1c6c0…

MALICIOUS

PDF

87.9 KB Created: 2021-09-22 11:09:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7f50311551821c6590ccb5db389b4930 SHA-1: 0d98b06f40a6a308afa60f1dc8b7a13d80f67b93 SHA-256: b8908a1bbab1c6c019b247eedd407b90d944aadf7e9b0d616235dbe3e0f8b368
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and it contains numerous external URLs. Several heuristics indicate it functions as a link farm, with some links pointing to compromised WordPress sites. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://medvor.ru/uplcv?utm_term=hentai+games+rpg+android PDF link annotation
    • https://krainaogrodow.eu/zdjecia/fck/file/mexomaf.pdfIn PDF document text
    • http://bon-mar.com/fck_user_files/file/muvogujexuz.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/93437512489.pdfIn PDF document text
    • http://minerva-collection.net/files/files/kowapamid.pdfIn PDF document text
    • http://papienbanana.com/user_file/file/kuxujujudezixano.pdfIn PDF document text
    • https://kurtoglumob.com/upload/file/gekerobu.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0cbe09ee1---94837685464.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/xetefepobumamuvaxiv.pdfIn PDF document text
    • http://maysoi.com/hinhanh_fckeditor/file/wawemasavij.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/33a3245d0d6bdcb86ecdb79aee7b9e6f/towoneku.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/9823294514.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/gudaxital.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/fec0884a4bc169f5fd419414a0157253/44935267413.pdfIn PDF document text
    • https://regionalhealthprogramsww.com/images/file/93197158943.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/93245901726.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/gevenu.pdfIn PDF document text
    • http://edituj.cz/res/file/fadukefeloxexevav.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/vavukeges.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/dq2nqb3c6707kf368r06mc3iq4/kegazelowolapiravexejufar.pdfIn PDF document text
    • http://stmarysharipad.com/userfiles/file/nofopesatezuk.pdfIn PDF document text
    • http://phunphu.com/userfiles/file/widularikadudas.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/nifirekid.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/96036296864.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_off0000f60d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010e1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1F 16904 bytes
SHA-256: 80dfdd1adfd32278a548666680ff64cf33c05669b3d59a87ff94570bb3139994
font_02_sfnt_off00013a0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A0F 10680 bytes
SHA-256: 60115d0a167d06ac46f5ab2d9cf27392a755d865b108ca331ec1b2c3f8f03fa1