Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b3370cb7753e688…

MALICIOUS

PDF

72.4 KB Created: 2021-09-21 06:11:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1e449a884746107e75058b4946e0ccb0 SHA-1: 2a22c9ad651f090e293c638b6f7861755bcc5060 SHA-256: 6b3370cb7753e68823645c84e9b63ba07aff400174121ee26011860b940fa469
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous embedded URLs pointing to various domains. This suggests the primary attack pattern is to redirect users to phishing or malware distribution sites, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oniceh.ru/uplcv?utm_term=kotlin+hide+keyboard PDF link annotation
    • https://juvelyrikoscentras.lt/Files/file/91673412425.pdfIn PDF document text
    • http://gabortech.com/admin/file/lomosogodokewoviguzelezu.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/12894698617.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/vagikevuneronajigisaja.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/3902329782.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/dozanebizuxegologajikumu.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021091701071336.pdfIn PDF document text
    • https://delphin-restaurant.com/ckfinder/upload/files/16174153642.pdfIn PDF document text
    • https://franciscojaviermoreno.com/DocsCKeditor/files/28347835018.pdfIn PDF document text
    • http://maquinandoysubastando.com/dleyes/admin/fotos/file/17755737142.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/50283715884.pdfIn PDF document text
    • http://revize-elektro.info/UserFiles/File/44227272721.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130f1299a711---76599133184.pdfIn PDF document text
    • http://xn--q20b13r9leepaeb.net/upload/file/202109160854145437.pdfIn PDF document text
    • http://pscworld.eu/ckfinder/userfiles/files/29311610585.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109210308483258.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/riwubijisudakezara.pdfIn PDF document text
    • http://obkladlazby.cz/userfiles/file/22860255706.pdfIn PDF document text
    • http://dobrejaja.com/Upload/file/43726583959.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rosabiropejorijan.pdfIn PDF document text
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/finoruvafaseriwajad.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/fadewodunifepu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b5e53cd0b---70744994447.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/163098982691.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/66850690588.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/14702248931.pdfIn PDF document text
    • 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_off0000b775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB775 17052 bytes
SHA-256: 166554e38383d13c80134597a80890d2b2554214136f8f099e8ce8fb0b04f5ca
font_01_sfnt_off0000e44c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE44C 10516 bytes
SHA-256: 98fe778d707ff10d3277ee38a1a8cbebd2985d07dfc08b5b2d631a2a9c1dfa2f
font_02_sfnt_off0000fc20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1