Malicious PDF — malware analysis report

Static analysis result for SHA-256 c852fd43ea278132…

MALICIOUS

PDF

85.0 KB Created: 2021-09-19 10:18:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 258c1e8721042fa4ca335e238464dbdb SHA-1: 7cf59df693d8e6e7e5db89cac123d1d5889cef7c SHA-256: c852fd43ea2781327c6accecbf7c0de90446d9b2149a8858b0789caeed88a7f8
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm patterns, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious websites. The presence of compromised CMS upload links further supports the malicious nature of the hosted content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://cructi.ru/uplcv?utm_term=a+browser+is+an+example+of+system+software PDF link annotation
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/44835913430.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161324318b8e8b---xewulumefujemefamup.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613453869c582---fukafokanu.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/wezigo.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/gafifoduri.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/63408706593.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/fasugi.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/57015915234.pdfIn PDF document text
    • https://medicabg.com/uploads/wysiwyg/files/lisewusanedezejud.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/19330967593.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/18826350906.pdfIn PDF document text
    • https://inunekocp.jp/mailmagazine/upload/files/monerosuzarakuri.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/feruvakafejapalizex.pdfIn PDF document text
    • https://myphambambi.com/webroot/img/files/98435342902.pdfIn PDF document text
    • http://konsultacjenaukowe.eu/Upload/file/28143269740.pdfIn PDF document text
    • http://mawratanews.com/armedia/uploads/files/24855122227.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16135eb4837226---dofejab.pdfIn PDF document text
    • https://stoneappeal.in/FCKeditor/file/49410733870.pdfIn PDF document text
    • https://newsale.linyn.mobi/upload/ckeditor/pages/files/falubivetobadugam.pdfIn PDF document text
    • https://xyoaa.org/sites/default/files/files/73950159696.pdfIn PDF document text
    • https://zagi.hr/files/40051517542.pdfIn PDF document text
    • 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_off0000e5ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AB 10940 bytes
SHA-256: 53192103c29501dc53e431b0ba8a2989402c2d19c7956370106a244f6e53cf71
font_01_sfnt_off0000feee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEEE 17976 bytes
SHA-256: 7e3b3feb5da37e6bcec0a71c2ea0cd020486efd2b86dcbc7ed5ca0b8a497642b
font_02_sfnt_off00012dba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1