Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef3e8353b52399fd…

MALICIOUS

PDF

71.6 KB Created: 2021-09-11 22:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 14539d33549e66f7588ddc6af7ffbb27 SHA-1: d24afee622c09357c084839f7033af4c6afe2702 SHA-256: ef3e8353b52399fdd671863bdb849bc58187b3e08afe8d0265bbf4010dac7030
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous extracted URLs suggest the document is designed to redirect users to potentially harmful websites. Although no scripts were explicitly extracted, the presence of PDF-specific heuristics and the overall structure point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://tucholainfo.pl/userfiles/file/kovotur.pdf In PDF document text
    • http://cyc.cz/pictures/clanky/files/kijinimokomalomiwa.pdfIn PDF document text
    • http://soundspace.eu/Upload/file/maxakivovijowilineva.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/56085639035.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/55332767375.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/87752310887.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/65918324243.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/dibodobep.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/37607572326.pdfIn PDF document text
    • http://sutinlawkrabi.com/ckfinder/userfiles/files/35773636451.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/difolabukajiro.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea05e4fae6---mokebililowevamum.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/99724598286.pdfIn PDF document text
    • http://sinostandards.net/upload/files/ziralenumikebagorinitekiw.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/vsgscjp236c5g8vta6ahqh4us4/50518216937.pdfIn PDF document text
    • http://pastoret.it/userfiles/files/lovisoxu.pdfIn PDF document text
    • https://xn--49st2et51duvk.com/upload/files/41157905130.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210902012738.pdfIn PDF document text
    • http://brlairport.com/images/file/24747073238.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.excore.hu/ckfinder/userfiles/files/vapumabubuzexevo.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/37585660272.pdfIn PDF document text
    • http://obkladlazby.cz/userfiles/file/92057179355.pdfIn PDF document text
    • https://psystat.net/candyticket/uploads/page_images/files/gofukazo.pdfIn PDF document text
    • http://princeverma.in/uploads/files/80340911381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=instagram+dp+saver+appPDF 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_off0000b829.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB829 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d03b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD03B 16096 bytes
SHA-256: f814f6f5d8f40a7f2f97e7e7686b1dd28d1389d210d9219a6dbb57d21b51ff00
font_02_sfnt_off0000f9ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AE 10496 bytes
SHA-256: f1e07f944c6a48acedd213ba350aff8931a343e3006d7b6f84d8565092998d1c