Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8122518638d352a…

MALICIOUS

PDF

82.5 KB Created: 2021-09-15 17:20:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 61eb4f1c995f5d4c54cf83bd19480fda SHA-1: 6c6b46816df53903b4e4d33750f4fd1e33bb361d SHA-256: c8122518638d352a508be370fea605f08961deb78fc29f98898cb82ffa10d425
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, indicating a link farm designed for redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with a malicious document delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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=accubattery+app+review PDF link annotation
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/43cc17df7763c15878d7fc3f312dc56c/wogirufugumepijasuwabotow.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/9373801c5ef233a5891774e41f3844bb/didoje.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/e2dc2f4e2b278709404d27c72217029d/81629277984.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/laribezuzarepixar.pdfIn PDF document text
    • http://rescue119.org/userfiles/file/43706507823.pdfIn PDF document text
    • http://akgwealthplanner.com/crm/files/97708307486.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/21174387227.pdfIn PDF document text
    • https://movie2book.com/userfiles/file/63317837045.pdfIn PDF document text
    • https://daqing-jewelry.com/uploads/files/202109091816557371.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/bomeduroneb.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613994003ff52---72917918777.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/jojirodix.pdfIn PDF document text
    • http://putzlappenborner.at/editor_up/42722145841.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/4415343977.pdfIn PDF document text
    • http://kronospan-mofa.hu/editor_up/koxixabu.pdfIn PDF document text
    • http://leasingtowers.com/ckfinder/userfiles/files/rofepusazug.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/49528431271.pdfIn PDF document text
    • http://xn--b1adbbbaeqjtsflbfms0e.xn--p1ai/pict/file/buzejuxabogujetatuvixexom.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a339f819a997df2d7073d0e528c270af/walosutugedelenumuziso.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/42529649519.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/lusilitewamifa.pdfIn PDF document text
    • http://thecountryclub32055.com/userimages/gejovepoziwojamosurez.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_off0000df0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0E 10416 bytes
SHA-256: 5f658e94ac8b738aed152ec9b4f848102d5a3dfe0432aae1c59b6767e9b81a3b
font_01_sfnt_off0000f6af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AF 17572 bytes
SHA-256: 308728ad63a25d3d31306a7537523f1b05d578f2d67a8d32585f1389585eb87c
font_02_sfnt_off0001247f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1247F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1