Malicious PDF — malware analysis report

Static analysis result for SHA-256 8da58c931c11c107…

MALICIOUS

PDF

75.4 KB Created: 2021-09-08 23:25:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8961fad4d2c46fc1254a27f8a6f3a845 SHA-1: 3cae03d6629b329c715ca1be16b4fef532ad2c38 SHA-256: 8da58c931c11c1072cd832f36b45de651ea7d6bf26b153f7a342b08ed4f284f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains numerous external URLs, many hosted on compromised WordPress sites, suggesting it functions as a link farm. One URL, 'https://coretry.ru/uplcv?utm_term=roblox+new+update+2021+apk', appears to be a lure for potentially malicious content. No scripts were extracted, but the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://coretry.ru/uplcv?utm_term=roblox+new+update+2021+apk PDF link annotation
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613048cad3f26---39192699688.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/68291416400.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/24132678275.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/bebepiravukiroguvaje.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/35689979349.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/qecv63ijuftpmkj97be8irgcrv/78854534601.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/16772846312.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/mejusetiwiwimixitizewag.pdfIn PDF document text
    • http://sireny.net/share/files/30792724580.pdfIn PDF document text
    • https://hidropomp2008.com/uploads/userfiles/file/22069890921.pdfIn PDF document text
    • https://armature.ir/cache/fck_files/file/xanogifatevirukemujose.pdfIn PDF document text
    • http://podiummoda.ru/userfiles/file/vejokoxugitofule.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/20905243308.pdfIn PDF document text
    • http://letdentalab.com/img/files/87477495099.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/15616862503.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/20752452546.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/jefmr814cmemt8rib4r6lk2bp3/87631263127.pdfIn PDF document text
    • http://xn--42cfa4ewb0a0b3fwh.com/imageupload/files/vusudapagiruzemokofudoxoj.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371d19a7820---regalutegera.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/10583306573.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/85730805865.pdfIn PDF document text
    • http://samtekelektrik.com/files/97314710242.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_off0000c247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC247 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA59 17168 bytes
SHA-256: b5a22c37d5011027ff59251c0176af51e46c31aeb9dcd484d35ad5c021d9e3f7
font_02_sfnt_off0001069f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1069F 10884 bytes
SHA-256: d4e5ae829967521ec82ba5d34933f172113d7db3a3cc477f6a079d486e24f064