Malicious PDF — malware analysis report

Static analysis result for SHA-256 66496b5f625607f7…

MALICIOUS

PDF

84.0 KB Created: 2021-09-19 13:48:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 298188ad6b82efeae662486d30f629de SHA-1: 8e1947edf0f6dbdf6b2e16f584499e5259c95dd3 SHA-256: 66496b5f625607f7587b78cddfb37c8a10ba14e67f252751a3ea97f035eb1d49
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that function as a link farm, directing users to potentially compromised websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates these links are spread across disposable hosting, suggesting an attempt to obscure the true malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://medvor.ru/uplcv?utm_term=little+house+on+the+prairie+pdf+free PDF link annotation
    • http://drsrkbedcollege.com/ckeditor/ckfinder/userfiles/files/47769343477.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/gurivawerobuluwez.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/79ee8f821561fb556634d170ca2a7524/kalawemaditegibilugezixe.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/seziwugojawolo.pdfIn PDF document text
    • https://doublehaircenter.com/upload/ckfinder/files/92362084237.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/regod.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/takekunaki.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/11816958942.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/82261455815.pdfIn PDF document text
    • https://gibidesign.com/fckfiles/file/99257499621.pdfIn PDF document text
    • http://xn--j1aii.su/userfiles/file/29784842815.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613431f7cebc7---neroletisu.pdfIn PDF document text
    • http://phatnang.com/media/ftp/file/viluxawipo.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/e575d2e9e1b11f1da094e0092fc78d00/64011380526.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/74332779007.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/26178063528.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2ee946b3f---74906479040.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/6740810842.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/91270332386.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/vojuko.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/161364177d37ae---8542064417.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/taxitosokukufurufejek.pdfIn PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/faxejifi.pdfIn PDF document text
    • http://dichvuketoanvn.org/uploads/files/60137276528.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_off0000e3cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3CF 10652 bytes
SHA-256: 6e95ddce24b7c0884c64e2614af604f5032c38bce3de0b5b6661de3cd5c30889
font_01_sfnt_off0000fc18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001142a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1142A 17764 bytes
SHA-256: 6d2808e7a8dfe196338b5b5c23765b343e675bec5f7c1d4e169d637068754b5b