Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c8effc2223ef088…

MALICIOUS

PDF

83.2 KB Created: 2021-09-23 05:14:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 62c2bfec700a443a221eadc5ff5e2ba7 SHA-1: e50b255ef2172a1b34414c7caca3abb9101d84b1 SHA-256: 3c8effc2223ef08842a2d4f373b316f9ba775ca05ba6ba25c0fd3555cd9f173e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicating a link farm designed for redirection. ClamAV and ML classifiers flagged this file as malicious, specifically as a phishing trojan. The presence of external URIs and link farms suggests an attempt to lure users to malicious sites, likely as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://www.stock2morrow.com/ckfinder/userfiles/files/sukajafujowiw.pdf In PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/81495637459.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/59597101968.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/949f9aa8cd6935f17c4a82d92f18ebad/11267523510.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210908124617.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/telosox.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/wajopitenezita.pdfIn PDF document text
    • http://ty-int.com/files/files/48013745529.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/63595343301.pdfIn PDF document text
    • https://leuphuotcamap.com/uploads/image/files/70406208345.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/fuvok.pdfIn PDF document text
    • https://praktijkbinnenstad.nl/file/54553133077.pdfIn PDF document text
    • https://j26clean.com/upload/files/80715655319.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/96398054743.pdfIn PDF document text
    • https://lazeo.nl/userfiles/file/wifofupinevazojoliso.pdfIn PDF document text
    • https://biographiewerkstatt-singer.de/userfiles/file/87407832919.pdfIn PDF document text
    • http://ecole.ru/text/images/file/42526517135.pdfIn PDF document text
    • https://jensbrode.de/files/file/kejow.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/l5f50v9f9l1q4b344b6kesbmk0/48639753101.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614350b174e2b---41306954425.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/15888673669.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/juwarasiponavokavames.pdfIn PDF document text
    • http://houselandia.ru/files/juwewoxigitomoderixi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=android+actionbar+searchview+listview+examplePDF 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_off0000db74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB74 11152 bytes
SHA-256: 2d537618ffd9b15687a9fd6f53f2c815825aaf222f60032f3dfef54d49b915ec
font_01_sfnt_off0000f529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF529 18308 bytes
SHA-256: ae547689fb1663c3d98c4d5492c6cd80fa38ccf66ee2f2e203927f9deea17df0
font_02_sfnt_off000124f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1