Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a9616f7e4cbe2a…

MALICIOUS

PDF

87.0 KB Created: 2021-10-09 09:21:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: df5d166bd2d4515f098e6ebb463abbe7 SHA-1: 884e90c67dd098ca561e82e0adaeffbc1157a226 SHA-256: a7a9616f7e4cbe2a6da5166a959787b1613dd33475a25190e343a1a7b1b5c217
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and ML classifiers indicated a high probability of maliciousness. It functions as a link farm, containing numerous URLs pointing to potentially compromised WordPress upload directories and other disposable hosting sites, suggesting an attempt to distribute phishing content or redirect users to malicious sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://onyx-innovations.com/assets/ckfinder/userfiles/files/75230197981.pdf In PDF document text
    • http://studiofelician.com/userfiles/files/39750918462.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132e975d44df---pilup.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161581c6ea6310---88290762971.pdfIn PDF document text
    • https://alwaysthesame.pt/site/upload/file/64262947235.pdfIn PDF document text
    • https://media-get.ru/userfiles/files/pususamuru.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/31050768875.pdfIn PDF document text
    • https://dottoridegregorio.it/public/file/11145307745.pdfIn PDF document text
    • http://seamacros.com/upload/file/52255508924.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/zajubozidixozirut.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/zabetajufoboniti.pdfIn PDF document text
    • http://greenflameenergy.com/userfiles/file/89335238476.pdfIn PDF document text
    • http://buddhavihara.net/userfiles/file/wotefejufovepo.pdfIn PDF document text
    • https://i-try.tw/upfile/files/2021/09/02/rejezilupategosinubava.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/98593995298.pdfIn PDF document text
    • http://datcat.vn/2018/file/barunotuvexof.pdfIn PDF document text
    • https://likeevent.it/writable/public/userfiles/file/tojogujitukegerudulubox.pdfIn PDF document text
    • https://chambres-a-la-ferme-plouzelambre.fr/userfiles/file/basukoni.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/fd0a56226e61f3fe2a04cc504bf01647/31515608.pdfIn PDF document text
    • http://domkomplekt34.ru/attachments/file/44309519726.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614048205874a---gubejodopubotokejekodural.pdfIn PDF document text
    • https://kuzeyilac.com/resimler/files/19001040778.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/jupevaroduzek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=milfy+city+save+file+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_off0000eff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF3 10628 bytes
SHA-256: a16a811333ae416f9caa39e83884ed878cb2e527789bee9f13874bd4c6fd40ef
font_01_sfnt_off0001087c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1087C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001208e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1208E 17468 bytes
SHA-256: 166b91a421581a39220325852678bdbb355c620b767be881a349b2cc33f20be8