Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8884638f64637ba…

MALICIOUS

PDF

92.8 KB Created: 2021-06-29 02:41:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 7177ae7e84e9688da9ee0c63cb5b60aa SHA-1: 9a5b6958771a956f588827ddb04e99320444351c SHA-256: a8884638f64637bacc685a947b2c81e4f1c943293cbf9137a8a90f500f9557ab
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This suggests a multi-stage attack, likely for phishing or distributing further malware. ClamAV and ML classifiers flagged this PDF as malicious, indicating a high likelihood of malicious intent. The structure and content are consistent with a phishing lure or a downloader for a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160820a97cc488---13467114510.pdf In PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/42174643336.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/bed6dc19211c736cdebddb5b0328756c/mudotuke.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16079ded4bc7b8---57242128077.pdfIn PDF document text
    • http://maternites-catholiques.org/ressource/site-image/files/bebutazeganinanoxonef.pdfIn PDF document text
    • http://moonlightmontessori.com/upload/files/2083507182.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/xagutomasetikozegodisixo.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/346b7e16a338ee76e01ad15ba105d678/zoriwufuz.pdfIn PDF document text
    • https://minegociomiweb.com/userfiles/file/93090597696.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bf84ad693a---nojujanimakudaxipusojasu.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/92345c7e888c610175f2d07f13d6456f/12936948111.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c72542df0a1---56820552731.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/kifunaw.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/vupaxinezo.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/sb2qdt8d0uqq11f1f0mn5868gi/dowusejotepabekujo.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ff515458d6---93556936606.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad36055bab2---barunudenafe.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/rls912q82skol8785hd6tqgn95/madodinopelapidip.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/m8iaq7uub31vo5c26j422eui1i/jozeretigajelonujitut.pdfIn PDF document text
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/d1o9seajsu6r29lhddlcjq4p85/sowebowotovimejumop.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/14929489875.pdfIn PDF document text
    • https://bancodevida.com/bancodevida/admin/images/image/file/pedanomokabuwisit.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/gorijafakiretimid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=bible+say+about+eating+porkPDF 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_off00010906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10906 10928 bytes
SHA-256: 544760f588427d4892f2180799955acbd5fc34ab1199ab8a866b580997ca5f0c
font_01_sfnt_off0001224f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1224F 16820 bytes
SHA-256: cad3a3d7a55b28a442fea3d969d9a57ca3c0e2460ec8c13fed8fed7537e75985
font_02_sfnt_off00014dc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1