Malicious PDF — malware analysis report

Static analysis result for SHA-256 393efaf91f1120e3…

MALICIOUS

PDF

69.9 KB Created: 2021-10-10 04:07:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 23fcaa4838a251b2f56cec75cc317807 SHA-1: 4c7847e47d899fbb4cc6786fb6a079003370c42f SHA-256: 393efaf91f1120e32a3ad87d1a30402f439b2bf99a45d34aa046c3bc78bd4711
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to external websites, many hosted on disposable domains or compromised CMS uploads, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. No scripts were extracted, but the overall structure points to a malicious PDF designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://riverside-plaza.com/upload/userfile/files/41094435689.pdf In PDF document text
    • http://santinitravel.co/files/others/venafe.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/87348285124.pdfIn PDF document text
    • http://rollfactorytogo.com/uploads/files/tapukiwekixozakemazejuk.pdfIn PDF document text
    • http://www.ville-dammarie.com/ckfinder/userfiles/files/3202528492.pdfIn PDF document text
    • http://frigotechreina.com/userfiles/files/69425497161.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/59594080022.pdfIn PDF document text
    • http://geonatlife.es/ckfinder/userfiles/files/19863057788.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/161351a698ae6c---34332164886.pdfIn PDF document text
    • https://www.informacion-indoorclub.com/boletines/img/file/2319629752.pdfIn PDF document text
    • http://autosklo.sk/pictures/file/82951033177.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/78294015933.pdfIn PDF document text
    • https://5udua.com/contents/files/telego.pdfIn PDF document text
    • http://esistore.com/userfiles/file/zefadaru.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/ferodujilasopifivifiki.pdfIn PDF document text
    • https://braindevelopmentmaps.org/userfiles/files/gibezobediporez.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137ad9e78d70---36579649597.pdfIn PDF document text
    • http://bodybybodyology.com/ckfinder/userfiles/files/47688379162.pdfIn PDF document text
    • https://www.thaiahpa.com/flash/files/lawewojasale.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161321a83ece2e---koxerozeluzajufe.pdfIn PDF document text
    • http://xn----7sbbgprpk7biiq.xn--p1ai/admin/ckfinder/userfiles/files/vozazugap.pdfIn PDF document text
    • https://dellrein.ru/content/file/muwinabix.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/2a55c2202d2ba677b64faf2ee1334172/29114339166.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=cancer+in+sinus+cavityPDF 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_off0000b337.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB337 10368 bytes
SHA-256: 1c89fea917105f59a206370445c578bb703986a705f6bef1e2486c57c97640b8
font_01_sfnt_off0000cada.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCADA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e2ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2EC 15560 bytes
SHA-256: e51d343b991ad1259a1efb8f3a817b2291a81c40f5d157ce8cfce0d6ed211ae0