Malicious PDF — malware analysis report

Static analysis result for SHA-256 158ec0d1682e93e3…

MALICIOUS

PDF

74.7 KB Created: 2021-09-07 04:28:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 59b4d62070c55480d98bd7b9846f8e9d SHA-1: ca11649dd0152b18cbedc53903bd63f681c2a7c2 SHA-256: 158ec0d1682e93e3dd811b81fa4c94c5b7319e9a11fe85683556c5b0a111ea68
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the links and the PDF structure imply it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=electrical+safety+in+industrial+plants+pdf PDF link annotation
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/d5f39718f2525c17c36d05060ce5626c/22381773462.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/7a63b66ab78c5ee755ce1c99f9a54640/61946662401.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c0f157484a8---xasogebosik.pdfIn PDF document text
    • http://clarkstownhs64.com/clients/2/25/255c49a504cbad61718694d8b78dfcdd/File/2235255405.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/fa587d949559a2a0c87d8340eb46d450/2599337764.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/7cc418a6e5a6347e046167dbea9e4463/sigebogevuxumox.pdfIn PDF document text
    • http://haai.org/upload/file/86405541001.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/28062567988.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607f891311ea7---84796157703.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/vibidodumaxogiwamorin.pdfIn PDF document text
    • http://tipiland.net/upload/file/tudutobirelumaguze.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/99285745273.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607371a30a1fb---jamesogel.pdfIn PDF document text
    • https://khonggiansangtao.com/platformecom/img/upload/file/jelewefebilijibogilobod.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/gidadozijowufo.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/f9db43aaf0512aaa99475f1bd4c89fda/80420197283.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/65fc55be2b8518b5bed78542b0874418/7985067192.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c0f4d5602---segepilafuvupesetene.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/anlgkmh32hnfu4utt6hbb1dto6/66330339732.pdfIn PDF document text
    • http://ebsenglish.net/_UploadFile/Images/file/82642218912.pdfIn PDF document text
    • http://venturahigh1967.com/clients/40640/File/mozowuvapobebeki.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160707db0ce502---93355369066.pdfIn PDF document text
    • http://splhardware.com/UploadFile/file/2021090303550073499.pdfIn PDF document text
    • http://onlinepravenconsultant.com/uploads/wysiwyg/files/92902144387.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_off0000c3ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3EC 16040 bytes
SHA-256: 39a2216bf94f9a07f05c47077d5fe2da8e65ba886ff290385a6a77d0ab3a5650
font_01_sfnt_off0000ec97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104AE 10688 bytes
SHA-256: c9aac197b1bee95d138b4beac81741f4258ed2f364acd62c8577253ba28bd704