Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b5c421bfa506eb…

MALICIOUS

PDF

80.8 KB Created: 2021-09-14 04:31:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e291f9cfad4675f7d22ffcda625c9dd1 SHA-1: e2213ae2a7287f71f4a0d63c245a981bf0a2e9b5 SHA-256: f4b5c421bfa506eb63b2043f6ad11b225971c1c29c75e989176848353e636949
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm directing to numerous external URLs, many hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. While no scripts were extracted, the structure and URL distribution suggest an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://remont-bez-zabot.ru/files/file/2864506108.pdf In PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/2942d8d89319e55fceee552a3eb51185/kobomajutifunakojekajokum.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/ab41c1d3b6fe47164e546dd42c0b5516/75817977633.pdfIn PDF document text
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/finikele.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/naxavu.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/fukogomuwepubilovab.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/wafupo.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/biwuxofuluvot.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/2m907j07hbv7q1v3p2hn7font3/fuxifibosopesiwu.pdfIn PDF document text
    • https://bbox.ru/images/shared/file/18897588696.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/22182112852.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/36918677273.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/besoxaxezagaf.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/10112854493.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a141a00fcd---malapaxuzibomudoseb.pdfIn PDF document text
    • http://ambulatorioveterinariocamali.com/userfiles/files/xizudowasevuvozazipifi.pdfIn PDF document text
    • https://curtain.jinware.com/upload/files/60911846373.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16139b41d09bc6---tetenogirawikijo.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/bizesavugawifamulada.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/newakiwagulisojigikatuviv.pdfIn PDF document text
    • https://gtnet-engine.com/ckfinder/userfiles/files/barotozuwipisisaginaw.pdfIn PDF document text
    • http://shop-exclusive.cz/userfiles/file/dezesiremegavatokoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=remote+play+androidPDF 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_off0000ce51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE51 10544 bytes
SHA-256: f1e78c52644f8f74a9f4f4bd5597b1861cbd980f9deaf540f02c2682598a08b6
font_01_sfnt_off0000e64d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE64D 21200 bytes
SHA-256: f0e3d3e4a93f3149579eca36c48981a4bc7b31f76b403cd4ec03824351714ba1
font_02_sfnt_off00011e30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1