Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b8acabeecf6a8f…

MALICIOUS

PDF

72.5 KB Created: 2021-09-25 08:22:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d471748ba41ddfa3a581c62d81bb3017 SHA-1: 3656acbdb01d81fbc23e722d2af11e8e1c791bf4 SHA-256: 21b8acabeecf6a8f9f23281ba06fb557834269d6f8ee17c59d1ed9061d4e27ec
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure points to a malicious document likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://gamepinleri.net/calisma2/files/uploads/kebuwanetotevi.pdf In PDF document text
    • http://rasmesafar.net/basefile/basefiles/dabemubigaradovu.pdfIn PDF document text
    • http://medica-brno.com/files/81734819315.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/15hm3glvj5hsge4uor4dipdk2p/gafuweto.pdfIn PDF document text
    • https://cebrium.ssnn.ro/images/mubopugatikafufunizupu.pdfIn PDF document text
    • http://yepuco.com/uploads/files/saxidolawapalilazategu.pdfIn PDF document text
    • https://ww170001.linebot.net/upfile/files/20210922185806.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/dijala.pdfIn PDF document text
    • http://musicpark-live.de/userfiles/file/58579400594.pdfIn PDF document text
    • http://1666-3668.com/attach/userfiles/file/virozewegosaloxanemize.pdfIn PDF document text
    • https://digireg.cn/upload/zizafaganovafo.pdfIn PDF document text
    • https://www.naabelectric.com/userfiles/files/62675565443.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/bilewibegebevisuzos.pdfIn PDF document text
    • http://adamslakeband.org/userfiles/file/57370138839.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/rexedefopupuzakuxukisavix.pdfIn PDF document text
    • https://datawire.gr/files/files/vatojilunaxazirenuleluw.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1d381f191---baxunik.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/h57m4e9csjcusts8nohb58d1n5/37094255242.pdfIn PDF document text
    • https://ysh.my/userfiles/file/bekojeludekukaf.pdfIn PDF document text
    • https://wittnebel.dk/file/zejedekedetetifosugivu.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161334334dc24a---pimusunan.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7500e53a4---namudosorer.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/93392130501.pdfIn PDF document text
    • https://infosantiere.ro/userfiles/file/84815559752.pdfIn PDF document text
    • http://tcihk.com/userfiles/29560638622.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=movie+maker+2021+free+downloadPDF 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_off0000b55c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB55C 17348 bytes
SHA-256: 23bff20bb685a033ade81ac51aa8cbf8e3a7475332902e951542cd973b097528
font_01_sfnt_off0000e229.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE229 10780 bytes
SHA-256: aef8350ff271f611a9e9ff968e21f4030e2e8af2fa88dc788ca674e88d9ff22c
font_02_sfnt_off0000fb13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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