Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ea3a18d9f31714…

MALICIOUS

PDF

76.6 KB Created: 2021-10-03 10:55:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 02751873582d8b95c57c575564505e2a SHA-1: 7f142c5591e58421491e64d6689f59a5aac4b3b6 SHA-256: 81ea3a18d9f31714484a13d2149920369b40bcc30e56d1aff8eebfecac314d4c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://odontologosmalca.com/images/userfiles/file/xumekumudosamipadalexopa.pdf In PDF document text
    • http://unite-chem.com/upload/files/zatukixebovepevamejezed.pdfIn PDF document text
    • https://gopherscopes.com/userfiles/file/23741872529.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/simun.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-9-20/20210920181646215608.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210928045857616.pdfIn PDF document text
    • https://virtrade.gr/userfiles_lybo/file/duziwanimera.pdfIn PDF document text
    • http://camdohungdung.com/upload/files/80773703637.pdfIn PDF document text
    • http://p-energo.ru/content/file/57341034031.pdfIn PDF document text
    • http://cpghollywood.com/userfiles/files/zirigegiwiwutot.pdfIn PDF document text
    • https://davaocarrental.com/images/file/donobexuxurafewagixa.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/tokexemunepaden.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150255ac4ff6---juditakoro.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614da57046d90---tepisuzelodoxitezonat.pdfIn PDF document text
    • http://usarsenal.it/userfiles/files/73874296224.pdfIn PDF document text
    • http://archiw.bibliotekalesmierz.eu/img/upload/files/mawirelipije.pdfIn PDF document text
    • http://mrcookie.tw/upload/editor/file/161400044807.pdfIn PDF document text
    • https://ph2020.org/FCKeditor/file/75087511010.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613490f12d037---vepuwemugajix.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/mijatopivojanedominaxo.pdfIn PDF document text
    • http://dreamsurgeryen.net/ckupload/files/94881223892.pdfIn PDF document text
    • https://mongolia-volkslift.com/uploads/files/51004178340.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/nejirosugujurebeso.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/fudowalarolasogimovi.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161349b5f34468---komome.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210913125133.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=the+nigerian+language+policyPDF 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_off0000c020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC020 10564 bytes
SHA-256: 0285664330e03078ed3c29b1c0cda2d2c76ddb884f63a3aec7458307338da0b4
font_01_sfnt_off0000d81f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD81F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f031.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF031 19964 bytes
SHA-256: 490848f487d3a8bffb026cefcb87f5b8c4195d76e24ccec2fb5d97cf5e1320e5

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