Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ac06d6b88baacc…

MALICIOUS

PDF

68.6 KB Created: 2021-09-25 21:58:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: df28cf31e87f929e6a8fdd30fb76e383 SHA-1: 1c6e84c2416da602ea21b2bee5c1b485eae39c41 SHA-256: 51ac06d6b88baaccba64f7d817e3782cb14fcbefe49c0088c6b9312b168c0040
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggest a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the PDF and the URL patterns are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://garglob.ru/uplcv?utm_term=home+and+back+button+not+working+android
    • http://miskolciharsona.hu/pictures/file/30713492843.pdf
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/161326e3c254bb---20607699033.pdf
    • http://rabwork.com/media/file/20980552713.pdf
    • https://sydneystudytour.com/accounting/userfiles/file/27222610090.pdf
    • http://geometrarontani.it/userfiles/files/bajinajen.pdf
    • http://satyavnetworks.com/fck_upload_images/file/kezigu.pdf
    • http://evo-models.com/uploads/userfiles/files/rejuwilabekukaka.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613952dd70d48---jozibozedojana.pdf
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/161457402e84bb---jekogidogegafaruf.pdf
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/c033cdd000e4119cde4b7f1ca9463689/14008108738.pdf
    • http://autowagon.it/userfiles/files/62472348003.pdf
    • http://konberdbio.com/upload/files/81129997278.pdf
    • https://callmarkinvestments.fortunekenya.com/callmark/files/20451795530.pdf
    • http://cropscipublisher.com/files/upfiles/file/betoz.pdf
    • http://goldenstarhotel.vn/images/uploads/files/48073845185.pdf
    • http://www.szphotar.com/admin/img/files/84658940936.pdf
    • https://tahitotfalu.hu/ckfinder/userfiles/files/32481440728.pdf
    • https://granitnet.hu/editor_up/81058885541.pdf
    • http://uforoi.com/app/webroot/uploads/files/95846267001.pdf
    • http://optimaglobal.net/ckupload/files/18742617009.pdf
    • http://sashtraayurveda.com/ckfinder/userfiles/files/lasubivupamogejurewaz.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1614542cae2857---sirixaniv.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000add4.bin
2a32600be2cb5ed9836346f69cc63010e553017fdeefd35f4af5932992e7a5d6
pdf-font-stream PDF embedded font (sfnt) at offset 0xADD4 10908 bytes
font_01_sfnt_off0000c6d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6D7 16792 bytes
font_02_sfnt_off0000dee9.bin
608a0dadddab4f4dd1117bc63e7e92173c5f6ce2a16f18ca29a6bc95b8b03b23
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE9 15244 bytes