Malicious PDF — malware analysis report

Static analysis result for SHA-256 a805af648157393f…

MALICIOUS

PDF

83.3 KB Created: 2021-09-18 10:15:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: bf1de7b3fc3707bff252c6e86857072a SHA-1: c5fec1e011b63f0a80bed334061d6bd9b6db7184 SHA-256: a805af648157393f9251a2c62bebd000b1a627e9d9dcf18f02f8aaea40274cbd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files, suggesting a link farm designed to obscure malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this behavior. While no scripts were directly extracted, the nature of the embedded links and the ClamAV detection as 'Pdf.Phishing.Trojan' point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://vigova.com/Images_upload/files/89021932318.pdf In PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb021cd79b---42755869285.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/gomixoxuzenuremot.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/gataneribuke.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/28803320159.pdfIn PDF document text
    • http://rebeccaosborne.com/uploads/bugekirumimu.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/nekurutozizeweg.pdfIn PDF document text
    • https://dailyhondaotomientay.com/upload/files/45721128230.pdfIn PDF document text
    • http://tulga.ru/editor/files/40561308718.pdfIn PDF document text
    • https://toliveinchristjesus.ceosale.catholic.edu.au/application/third_party/ckfinder/userfiles/files/9054103285.pdfIn PDF document text
    • https://mhreng.com/userfiles/file/87824524764.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/nebene.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/18923573470.pdfIn PDF document text
    • http://viprealestatebrokers.com/userfiles/files/48920344077.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210902_1D5EAB8E6E3E9F69.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/26981423076.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/27109688288.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161405e7612204---80942686157.pdfIn PDF document text
    • http://binhchuachay.info/Images_upload/files/xaxujawopemevagesifine.pdfIn PDF document text
    • http://hongdacable.com/d/files/jipuruxosujabazegiwu.pdfIn PDF document text
    • http://93564497.com/userfiles/tarodoken.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/xodalonozuno.pdfIn PDF document text
    • http://sitarofindiamd.com/userfiles/file/vusilukubitalaw.pdfIn PDF document text
    • http://blccy.com/userfiles/files/garosawelives.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/24665147263.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=dee+unglaub+silverthorn+human+physiology+pdfPDF 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_off0000df70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF70 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f782.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF782 17448 bytes
SHA-256: cdd6447bcf608b100a163794338bd88b517618fbcaafbc5e3a86f87b2f339cdd
font_02_sfnt_off000124ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124EE 11368 bytes
SHA-256: b877f8fa6e1ad99687686c85e8f7fa59729a155359670cd9407c9a98cf19e6f9