Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b5391ec38dc214a…

MALICIOUS

PDF

98.1 KB Created: 2021-09-08 13:54:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a226ce568c5a881db4b7a77d96b2b0bb SHA-1: 2ae495f0fd6c4ae19f51e3979d8d8c0a4032df3d SHA-256: 0b5391ec38dc214a42bdbc933c1b334806b405090e18adf15782bf25f2eb765a
126 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains a large number of embedded URLs, many pointing to disposable domains, characteristic of a link farm used to distribute phishing content or malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9875

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://phuocthuan.vn/images/pic/file/3048183340.pdf In PDF document text
    • http://allivecoat.com/userData/board/file/tipomopazedumibugoxuxowus.pdfIn PDF document text
    • http://www.gieskestukadoors.nl/ckfinder/files/files/56617172087.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/93662127126.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/7934359466.pdfIn PDF document text
    • http://aadcnfgl.netsociality.com/upload/files/wugogo.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/tixomesuwobavalanuxin.pdfIn PDF document text
    • http://kammerchor-lindau.com/file/jozofevuvukidaligasexav.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/dugopemabosedotalawuj.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/74944918951.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320f2939971---pifixasus.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/pewebumuxanezeviwo.pdfIn PDF document text
    • http://js-space.de/userfiles/file/42875479232.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/puzawizawu.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/jovokenon.pdfIn PDF document text
    • http://szpk.hu/_user/file/38890476771.pdfIn PDF document text
    • https://truckforceone.eu/upload/editor/file/99621464428.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16130926759537---worerepumasar.pdfIn PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/nokuxojigubomafuxon.pdfIn PDF document text
    • https://angel-juicer.com/FileData/ckfinder/files/20210905_FF13DF893D1BDCDC.pdfIn PDF document text
    • http://mikailang.com/userfiles/file/20210906005914_1556506929.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/43908150096.pdfIn PDF document text
    • http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/kizebesozufaf.pdfIn PDF document text
    • http://bsa-billiard.by/images_from_html_editor/file/37488397096.pdfIn PDF document text
    • http://e-menu.hu/editor_up/13278918746.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/c6344441a3caa0b9e7c6513af64014ad/niwodixut.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=fuzzy+controller+design+theory+and+applications+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_off00011826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11826 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13038 18272 bytes
SHA-256: c6e1a65c165dc585ed43faf682542a7c9bc6c79b67d34a6631025359fdf9446a
font_02_sfnt_off00015fc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FC9 11148 bytes
SHA-256: 8ec6cdc3ce7db03828bccd7af70365f0bbbf4e08fb465c9d3be535d5cda7393f