Malicious PDF — malware analysis report

Static analysis result for SHA-256 a36f53b8deb1556f…

MALICIOUS

PDF

107.3 KB Created: 2021-09-07 13:05:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 74bd3dc547f1af18c16f087474a71090 SHA-1: b01e98faf1b598b561302194bd7fd4748010c7c7 SHA-256: a36f53b8deb1556f62d300c58acbbe8026ed06e6b55b0c77373c6543e010a57a
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, containing numerous URLs pointing to compromised WordPress upload storage and disposable hosting. These links likely serve to distribute further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f81c0113405---suwilokawuronuxelupepez.pdf In PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcebd9a747---kufozixunipoda.pdfIn PDF document text
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/pijiwuredato.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/52337151698.pdfIn PDF document text
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a7a919dc4---25913900265.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a7dd235c0---54693990694.pdfIn PDF document text
    • https://bya-ingenieria.com/ckfinder/userfiles/files/16787015774.pdfIn PDF document text
    • http://ahchala.com/img/file/zotafawuramegu.pdfIn PDF document text
    • http://airfa.it/userfiles/file/xafamuja.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/9b189c0e76504dcee8757f5c838a2369/4209013052.pdfIn PDF document text
    • http://altinellerinsaat.net/UserFiles/file/12032763171.pdfIn PDF document text
    • https://www.asahinafunnels.com/wp-content/plugins/super-forms/uploads/php/files/leulkk1ptels38ns3e323c7gbr/93016836555.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/96184854954.pdfIn PDF document text
    • https://sce.tw/uploads/files/60cb02ddbdbdc.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/wogobozepunimaxeju.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/29346779250.pdfIn PDF document text
    • http://jucal.es/images/file/50628960864.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/21b2b2d07a7861328c182b56365dfa88/34105593283.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/40640863046.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/nidg41idmekq2bnq7i1p5ssg36/vovexi.pdfIn PDF document text
    • http://hocikto.info/userfiles/file/76419638223.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/92299136888.pdfIn PDF document text
    • https://ita.kru.ac.th/ckfinder/userfiles/files/tibuzedifexofoxivawatuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=mdg+and+sdg+goals+pdfPDF 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_off0001417a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1417A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15991 10244 bytes
SHA-256: f6cf03e155f48d058c24b8aba1edeb61c4dd205c97d3e231ebca46f0d505b83a
font_02_sfnt_off00017072.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17072 18252 bytes
SHA-256: 8761ae65c56044045360c7d1fc9aea39080047e8fa520f56df8c822c1a8317fb