Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8f8daf551ac6996…

MALICIOUS

PDF

76.1 KB Created: 2021-09-19 13:02:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c7666813c9dc7d36feb711f2742006f1 SHA-1: 6552751ff0dfbd3e59062e0b2431c34bbfcf3400 SHA-256: b8f8daf551ac699674416eb885cb25ab4e56b22b51f91f9b78844a91563f3d0d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous embedded URLs pointing to various domains, suggesting an attempt to redirect users to malicious sites for phishing or malware downloads. The presence of external URI links and the 'link farm' heuristic indicate a strong focus on directing users off-site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=tor+pro+apk PDF link annotation
    • http://imapbook.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/guwidudipegupuzit.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/61596587263.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/54173266987.pdfIn PDF document text
    • https://membermimpi.com/contents/files/48059662771.pdfIn PDF document text
    • https://poldercuptrofee.nl/site/admin/ckfinder/userfilesfiles/54775442041.pdfIn PDF document text
    • http://dptour.net/bot/ckfinder/uf/files/64584649637.pdfIn PDF document text
    • http://dietaltop.com/userfiles/files/55078387650.pdfIn PDF document text
    • http://screen.by/images/file/rasuvasa.pdfIn PDF document text
    • https://k85shj16h-561lt.com/contents/files/98187614653.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/sizibiwu.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/17420122746.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/kurutudopisomegowomum.pdfIn PDF document text
    • http://wawa757.com/uploads/files/sajugezezexejigotuwi.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sadevimejidoberilewixedov.pdfIn PDF document text
    • http://proallprint.com/userfiles/files/jidujenopilanuxobu.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/vegojumaguwoviwofumojudi.pdfIn PDF document text
    • http://sibmaxi.ru/userfiles/file/92852971863.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/52376626058.pdfIn PDF document text
    • http://sarljarry.com/userfiles/file/kokozakikomevo.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/xexubipupefasasebijet.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/pawuxajolame.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/mesupirepolikevexumemam.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/78132779980.pdfIn PDF document text
    • http://thegioituigiay.net/uploads/files/fidaxafivivakaratigud.pdfIn PDF document text
    • http://cluster006.ovh.net/~greeters/namur/ckfinder/userfiles/files/tepuvadenoj.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_off0000c77b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC77B 9660 bytes
SHA-256: 554ba3f11fd5d5aed65d12e6349554f50abde93107bb80878023f9ddcf73869b
font_01_sfnt_off0000dc8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8A 18052 bytes
SHA-256: f4947c67262deb1ea5463dcf48211f80b04ec0f8b7405c6f0a227ef88b26c32d
font_02_sfnt_off00010b6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1