Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6509ac100fd38af…

MALICIOUS

PDF

89.2 KB Created: 2021-09-13 10:58:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 412494c2928804c37738795a875a1df4 SHA-1: b22c1c84d74721c24daa03a792f4c3df3e3d1fef SHA-256: e6509ac100fd38af5ba3fb0ccb659a1ca06f536eba90acfbeee925aee65e228d
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The embedded URLs, while some are marked benign, are part of a larger pattern of redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161310dff73593---24082264038.pdf In PDF document text
    • http://lagrupacio.cat/file/xuvuxowozulepixedupa.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5c44c21da---43186318074.pdfIn PDF document text
    • http://tumwebthailand.com/ckfinder/userfiles/files/refitififi.pdfIn PDF document text
    • http://sprinter-lab.ru/content/File/30428060708.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16139bb59bce6e---58061896481.pdfIn PDF document text
    • http://stringladies.cz/userfiles/tidimuvitexixuzi.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/916695552.pdfIn PDF document text
    • https://onderdurdu.com/upload/ckfinder/files/19429506091.pdfIn PDF document text
    • https://anjingliar2.com/contents/files/56923368324.pdfIn PDF document text
    • https://andhimazhai.com/images/files/40015230281.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1e7a8ede2---20607001873.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/siwejebagefuxute.pdfIn PDF document text
    • http://top-caster.com/userfiles/file/potelubumebirubevepu.pdfIn PDF document text
    • http://sladkiy-ostrov.ru/userfiles/files/xamipoziroso.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a153e107ff---38827937388.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/72417253982.pdfIn PDF document text
    • http://adamex.ukrkarta.ua/fckeditor/userfiles/file/milawus.pdfIn PDF document text
    • https://cicadit.ro/UserFiles/file/benuxapuru.pdfIn PDF document text
    • http://nujhimachal.in/img/uploads/files/99339869742.pdfIn PDF document text
    • https://viveironativodevicosa.com.br/ckfinder/userfiles/files/85934865266.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=free+robux+no+moneyPDF 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_off0000f962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF962 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11174 18484 bytes
SHA-256: 3f44c5d96828dd84f127b1bc6fc2f7741e049facd1c902c540b21c821f507ab3
font_02_sfnt_off0001413a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1413A 10136 bytes
SHA-256: a892b6525f3b3ccc90dd4b73b929bf88de79b09d1eba7fbe45c8c072572152b2