Malicious PDF — malware analysis report

Static analysis result for SHA-256 d541392f61e3bab0…

MALICIOUS

PDF

69.8 KB Created: 2021-09-21 08:17:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 433036ba6d0e89fa02717276cee5dc5a SHA-1: 131b77e3b19d864c2cc760733891c02326bd46b1 SHA-256: d541392f61e3bab06a077b40ade2003db1229aedbcf56fdbb5be165b5ed54abc
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to disposable domains, suggesting a link farm designed to host malicious content or phishing pages. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nepalonlineexam.tisaracademy.com/userfiles/files/1577166190.pdf In PDF document text
    • http://cwpni.com/userData/ebizro_board/file/61976220838.pdfIn PDF document text
    • https://stauber.lt/images/files/repajigumufejalekadi.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/52095991179.pdfIn PDF document text
    • http://simoncaulkin.com/images/3854690453.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161428d6be6bf1---redilejowexomefefekev.pdfIn PDF document text
    • http://carscaso.com/js/upload/files/jasagixuravokotuvu.pdfIn PDF document text
    • http://flex-link.cn/uploadfiles/files/98356739607.pdfIn PDF document text
    • https://12shio3.com/contents/files/lupibakamogiwitulisojase.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/50655443900.pdfIn PDF document text
    • http://dgelc.com/userfiles/file/20210906104421.pdfIn PDF document text
    • https://kamionosnyelvlecke.hu/userfiles/file/18459371064.pdfIn PDF document text
    • http://1qjd.com/upload/files/2021-09-14-13-35-20-UQw0pH9C.pdfIn PDF document text
    • http://vatlieubaooncachnhiet.com/userfiles/file/vokanividedilojunop.pdfIn PDF document text
    • https://tlkingatlan.hu/kepek/other/file/82828849844.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rimidigabu.pdfIn PDF document text
    • https://giaiphapthietke.vn/media/file/files/89250874144.pdfIn PDF document text
    • http://vansuloi.com/uploads/userfiles/file/pubiti.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/kokewe.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614906c2d53f4---nalipi.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/rixefuporapidexogagonu.pdfIn PDF document text
    • http://mottaing.eu/userfiles/files/vekivojudotimiz.pdfIn PDF document text
    • http://hodori247.com/uploads/files/92953081671.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/vawunome.pdfIn PDF document text
    • http://koala-al.com/d/files/33052344863.pdfIn PDF document text
    • http://proallprint.com/userfiles/files/pivabawinivaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=pdf+to+xls+converterPDF 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_off0000b354.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB354 15312 bytes
SHA-256: bd8e61d5d506ec196e3ff92ff981e224c16ad5127b2ee52b717c56686bff1098
font_01_sfnt_off0000d9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F6 10384 bytes
SHA-256: 1086c372e71be1762524c2ffb4b338afcd52c04f22e559406758ccc411d29674
font_02_sfnt_off0000f1a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1