Malicious PDF — malware analysis report

Static analysis result for SHA-256 832f1667ec91d0eb…

MALICIOUS

PDF

89.2 KB Created: 2021-09-14 07:36:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dcb93bb6f648d7283e575c0212a5d85c SHA-1: 62906599de3edf52dc406db6e020d3c4dff4c359 SHA-256: 832f1667ec91d0eb730e31a827b80f356c5aeb470c7663a1f1cc68c565346697
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and a link farm pointing to multiple domains, some of which are hosted on compromised WordPress sites or disposable hosting. The presence of embedded JavaScript suggests an attempt to execute malicious code, likely to facilitate further compromise or redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://friulanapanini.com/images/file/84320117842.pdf In PDF document text
    • https://observatoire-omic.org/documents/file/guvewudiwemepuziko.pdfIn PDF document text
    • http://air-con.ru/upload/files/piguzuzugob.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5e8eea52c---10707200202.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-2/20210902103301959586.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/zivirolorido.pdfIn PDF document text
    • https://interconformity.ro/images/file/89934132466.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613518afeca87---rapatopaxoxuborubekexojog.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202108312331029734.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/23df9a38af239e9e3e0bf0a07c5c2df8/likituxibaketimojot.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/duzupezozokonatovima.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210910_E297AC929CEACC90.pdfIn PDF document text
    • http://ghefootmassage.com/fckeditor_userfiles/file/26369353625.pdfIn PDF document text
    • http://www.autoservis-hubatka.cz/admin/upload/ww/file/25065964792.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fdd3b14345---zopejutofika.pdfIn PDF document text
    • https://warsztatgdynia.pl/app/webroot/media/files/83510004733.pdfIn PDF document text
    • http://newgatedesign.com/Images_upload/files/58863743906.pdfIn PDF document text
    • https://anandalaya.in/resources/file/xejuraguraleta.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/revunuwodukenote.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/65719147408.pdfIn PDF document text
    • http://kuwaited.com/cote_dor_import/admin/ckfinder/userfiles/files/50081153210.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/tipubodobadoxoduletajuv.pdfIn PDF document text
    • http://carneiro-sa.pnh.pt/js/ckfinder/userfiles/files/6883113405.pdfIn PDF document text
    • https://semot.com/Store/userfiles/file/8353454433.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=como+personalizar+barra+de+estado+androidPDF 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_off0000f527.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF527 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3E 10784 bytes
SHA-256: 4be8545ca64103b6aab6344617f0466d58639b8c4fceb94b2af64539a3e08525
font_02_sfnt_off000125d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D8 18672 bytes
SHA-256: a297bec3a8d790566d12ade29dafa356316fd819451745b7cc0c29c718e481a4