Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b0413f0fa29dac…

MALICIOUS

PDF

76.6 KB Created: 2021-09-01 01:20:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c0d4ed3821ab1ef6658b3e9a98761566 SHA-1: 67b9b6e99219cf5bd0d0f36185fbc2870847975c SHA-256: 51b0413f0fa29dace373d9cf1d0f601dd971cb552c6e83c2b4e9f41c4d27900e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings point towards a malicious document, potentially leveraging embedded JavaScript for redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://aksusu.com/upload/files/rudajel.pdf In PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/3t1hse4t8kp91g90liha87186g/vedabejulofijulerovav.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/sojowetejoriranufeminix.pdfIn PDF document text
    • https://rarahil.org.np/ckfinder/userfiles/files/21632921803.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160837c8b5efe4---79882165161.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/550ebaa134ca325d3e29d6c6ce1eaaa1/mevovonapobaxorizokul.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/68023532032.pdfIn PDF document text
    • https://3drm.bg/uploads/pictures/files/leguve.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/90937060615.pdfIn PDF document text
    • https://cdpu.net/wp-content/plugins/super-forms/uploads/php/files/1437b21b5913d58789c685b2e0718179/60571892345.pdfIn PDF document text
    • https://eravukappalpalli.com/userfiles/file/vekozupekigixol.pdfIn PDF document text
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5f9a81082---zoxidok.pdfIn PDF document text
    • http://vhs1962.com/clients/b/b9/b967f936f519796c2a696a6ed1da67f9/File/zirirelenivegutuwij.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/kawuz.pdfIn PDF document text
    • http://grandviewgroupresort.com/upload/files/kulabasazodob.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/xuwakekazenovodavuture.pdfIn PDF document text
    • http://jinistudy.com/_UploadFile/Images/file/99133221045.pdfIn PDF document text
    • http://grawerlik.pl/userfiles/file/romuratisupenaridurama.pdfIn PDF document text
    • http://thietbianninh188.com/uploads/files/diganinitaruxowo.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/72404378728.pdfIn PDF document text
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744c2c47fc9---94053217529.pdfIn PDF document text
    • http://magendans.com/imagefiles/file/tipawepiza.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/tumivodosevofabason.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/bc32cf6d711cdee070475e34ae5ad5fe/zoxeju.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/fikodoruwisimumobuwo.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf3d409297---loviwirezuwajezox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=federalism+worksheet+governmentPDF 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_off0000c5de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF0 18048 bytes
SHA-256: ff05a3401601bac06deab33f0ee9134788c6f20361ba96c8f4738ca63e820d06
font_02_sfnt_off00010c1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1A 10916 bytes
SHA-256: 8f0ddb9e14558269235e370966e5e5b4d0cfcfc5ec196e128a72027c314c7cfd