Malicious PDF — malware analysis report

Static analysis result for SHA-256 98cb1dbfab73b79c…

MALICIOUS

PDF

69.8 KB Created: 2021-09-13 13:30:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3e06d7d874be704913d67d705d865541 SHA-1: d2e5600bdc40ebeaec734e4f5757ad5ba4954925 SHA-256: 98cb1dbfab73b79ce0f957f0c4ec674fa26f019a191c2bf0a7a643e347f2ce54
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicative of a link farm designed to lure users to download content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple link farm heuristics and the PDF_SEO_DISPOSABLE_LINK_FARM rule further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://elcampoeco.org/FCKeditor/file/50846165779.pdf In PDF document text
    • http://hoya-system.com/uploads/files/202109121256317900.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/tokuzujixafawobapuzolej.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pilejivewopizu.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/verodejitivirinoligo.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/pulozodakaba.pdfIn PDF document text
    • https://ta-taiwan.com/app/webroot/userfiles/files/60776810614.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16134d4842ea58---pawofepupumutepopuwakaba.pdfIn PDF document text
    • http://justsayhi365.com/uploads/file/rilut.pdfIn PDF document text
    • https://www.ventisilva.com.br/ckfinder/userfiles/files/ramefafojugezelewi.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/sadepebof.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/30436479619.pdfIn PDF document text
    • http://domuran.pl/files/file/80697730904.pdfIn PDF document text
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/5469620207.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/2734891167.pdfIn PDF document text
    • http://maternites-catholiques.org/ressource/site-image/files/kojopulukaba.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/josebido.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/73586972279.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/pogibesejutapisavibox.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16138d0edda6da---rufaponufame.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/714f497c3eb64afe56318b950eb8ce48/boginuno.pdfIn PDF document text
    • https://groupunsur4.com/contents/files/68068363974.pdfIn PDF document text
    • http://yuha.be/_files/file/pukejuwitenirodul.pdfIn PDF document text
    • http://obrienbuilders.com/userfiles/file/tezazaliwufonuvelenosig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=speed+meter+download+apkPDF 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_off0000b1c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1C9 15820 bytes
SHA-256: d9fcf162d39c7aab0dd75d27b974f0b35287c2b2406ab69e865ffae9668be03c
font_01_sfnt_off0000d9ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9EF 10544 bytes
SHA-256: e32b2f1ff853f5a104465ac2fc7cd3e9fbe7943c464716ed25838ca66797efb4
font_02_sfnt_off0000f205.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF205 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1