Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b4ad12bb186a56a…

MALICIOUS

PDF

156.9 KB Created: 2021-06-29 00:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: fa8e3c92db1352d2572ef2b12a652dea SHA-1: 8aa71fec7276a1975a67df70bb06419606a9b770 SHA-256: 5b4ad12bb186a56ad9e3a6a11b1aa8fdef12f47dacfa4199aea391f256ecf86d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the PDF structure itself are indicative of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://synerhu.ru/uplcv?utm_term=cambridge+6+test+3+reading+answers PDF link annotation
    • http://schodylux.pl/userfiles/file/tolijulepi.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/96330765192.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071895f6e2be---73690454552.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16078cff73f28a---xesemejijamana.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdcc4b1c550---votobeviwapubozezanefuwa.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/21859604753.pdfIn PDF document text
    • http://teplospectr.ru/images/files/wilexuretikokafafirik.pdfIn PDF document text
    • http://akinmedical.com/uploads/file/95266264346.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4b04abab7---vubixum.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/rv0644btuavvaumes7sspst4hp/60510426785.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/wagonadotetatemobanumado.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8c9f68c7f---32433962016.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/a3b2700d5b6939bedb8be82a767223b9/tijifovibenikowusaje.pdfIn PDF document text
    • https://salubrismd.com/wp-content/plugins/super-forms/uploads/php/files/56872cdfee98c00997df1fae118eff8f/komosigekewotoluzuripuval.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/jukedudofobuniwuduvibuwuz.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5dd079a6a---salominixebapo.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/dumasejimejerez.pdfIn PDF document text
    • https://tuvanthietke13-5.com/webroot/img/files/papasoxivibix.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1607e175ebc6a3---90016424248.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ada88b5538c---77212049440.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3aca51605---98612924450.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608226821fa77---povezukusugelusi.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/39299045044.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b91816edad---6465365186.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607653f4278c8---40102431142.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_off0002028e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2028E 18612 bytes
SHA-256: c9f0133f86a056abff13d1b23afcaf451a0228849c5ba2252326eecd8957a1ac
font_01_sfnt_off00023449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23449 11020 bytes
SHA-256: 1328f98e1a5e2a72442457262f31ce2919dd5185a06f0b9ff2b47893247bcf1f
font_02_sfnt_off00024dce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24DCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1