Malicious PDF — malware analysis report

Static analysis result for SHA-256 a861d9da38d1ea73…

MALICIOUS

PDF

87.5 KB Created: 2021-07-23 16:49:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8bcf5fcd8137e8fb6b7242bc0895aae9 SHA-1: f31de2a0d5401597b5bd65bbe6cadb9354bb4efb SHA-256: a861d9da38d1ea737a43fa0d505d2cb61a35eada78115a99f54ef960b96aa46d
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/55be9533cea3193e59e5c637fce60756/jezabofodosezakaloxunomel.pdf In PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ba8671de772---98488469064.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210706161209_1nsrrd.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160aa08c66f072---dirogowun.pdfIn PDF document text
    • https://506hlapeta.com/files/file/pebizexizola.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/e89c4f8f60046f1e19d01f6089c2aeee/jedupedisotif.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/ruvatifisonuweru.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/pn7o8au33l3r701i31l69jqdq1/gebepadajawalir.pdfIn PDF document text
    • https://educhina.mn/editor/files/lazoxumelujozix.pdfIn PDF document text
    • http://coutleelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/puwinenofubizuvudaxe.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160812e6f5147d---pukadowofarikukumaraz.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/zedoginoloxogigisawimiw.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/50153336922.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/25009d68f8dd38803019e9b4e97e5a06/furamiwivip.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/37089817813.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/42462855872.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/jasulo.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff3adbd7c1---5587326996.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/19877947990.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/50764196973.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/zusafajum.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/b0c7cc0caa605d5ff6c75a80c3d9655e/18841884387.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160910913efa0b---52424976299.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+design+architecture+firmPDF 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_off0000f1b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B1 16808 bytes
SHA-256: fa4bdb4861ce162c0489b58c68555698bdbf23c65847f084ead2d3da3564dc55
font_01_sfnt_off00011d95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D95 11052 bytes
SHA-256: 34173cc596a6e1095841299bb232588368d345b45df8c8b75f02a3e577b9ef7d
font_02_sfnt_off000136f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1