Malicious PDF — malware analysis report

Static analysis result for SHA-256 5223e7806b754fa4…

MALICIOUS

PDF

81.4 KB Created: 2021-09-17 17:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7fb456d76bc9c4a11fb09d6f7ce06546 SHA-1: 191168842f3fd69825de4e78eec52211a19805f5 SHA-256: 5223e7806b754fa48fc5b33051accd2505247f0a3c93946249be849f686fd483
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised or disposable domains, suggesting a link farm designed to manipulate search engine rankings or direct users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

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 http://cu-mbc.com/ckfinder/userfiles/files/buwazulug.pdf In PDF document text
    • http://ck-kutnahora.cz/gais/image/file/84938870467.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614467f6b8243---rojovajevozilagej.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/99963472046.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/zijizukoniluso.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/161346b9dd6145---17857862357.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/1614402b9391dd---53256683298.pdfIn PDF document text
    • http://hennel.hu/sources/elemek/file/40060837366.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/39019065691.pdfIn PDF document text
    • http://xn--82ca1bkibi6eufn5bh1b7i3e.com/UserFiles/File/lagemenikivovuwugusozigi.pdfIn PDF document text
    • https://kaptenhoki.info/contents/files/43666214725.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/cafd65fe516ba1a248eab6e7cbcddd59/87191357163.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/tubobivirabowo.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/jikabepabu.pdfIn PDF document text
    • http://sochi-polyana.com/ckfinder/userfiles/files/35481230504.pdfIn PDF document text
    • https://lrsinc.co/userfiles/file/65774294929.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/dazoripizikokizukimu.pdfIn PDF document text
    • http://sunrui-ti.com/d/files/zopipejoxemodesejunok.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/51643178893.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/fededilofiwividorup.pdfIn PDF document text
    • https://cooperadora.grupocreartel.com/documentos/archivos/65425928507.pdfIn PDF document text
    • https://kompaspt1.com/contents/files/76053295695.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=antutu+benchmark+android+apkPDF 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_off0000d83d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD83D 18252 bytes
SHA-256: 165d39af4211dbd6d7edd17da64fa84ae7033452ab80a00d2843abda9574ea96
font_01_sfnt_off0001070e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070E 10880 bytes
SHA-256: f4082ea9f90ef894049831783ec4b60ea6511276da0c30201c7c3001a802f0e6
font_02_sfnt_off00011fd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1