Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb9857583206b8d3…

MALICIOUS

PDF

73.5 KB Created: 2021-09-29 08:13:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c4062e9d0914079824ca2fd0a7d30623 SHA-1: 3271bc4710f17714839d786da84e8dd2a8a41aa6 SHA-256: eb9857583206b8d3880cba815f281f58f55ac25a3d232b2741650b66f54456ea
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external sites, including those hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious content or phishing sites. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, suggesting it's not intended for direct user interaction but rather as a container for malicious links.

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 https://khanoomhoteli.com/basefile/khanoomhotelicom/files/1534467659.pdf In PDF document text
    • http://viswinkelindex.nl/images/uploads/gakolagukukop.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1632685388.pdfIn PDF document text
    • http://rehahomecare.com/upload/editor/files/84131621536.pdfIn PDF document text
    • https://viessmannboilers.ca/fck_upload/file/10564314505.pdfIn PDF document text
    • http://retailjewellerindiaawards.com/userfiles/file/17187444206.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/bdshob2kdltp6qndnrlrbdjooc/pazagudonakarotorilifikal.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/65839441787.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/13632688458.pdfIn PDF document text
    • http://cssh.es/img/file/doduse.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/tixinatofojejiku.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109251305231197.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/nixejavugozeda.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/15140659498.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/dm14551hseb0rs4mf34tm9af3l/23029393788.pdfIn PDF document text
    • http://iknow.pl/files/file/20901392481.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16153ecdd63403---36271696052.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/vurisosusimatugisefimise.pdfIn PDF document text
    • https://nocnepal.org.np/ckfinder/userfiles/files/jawitijomotazuvonobi.pdfIn PDF document text
    • http://cutskytools.com/d/files/kukanix.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/kalawewidajod.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ihik5e5r6lklvk0qkdllik2tg7/bafejofunukuwa.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/e7e790c41edd7fa72beecb8ae8020b67/zulobexidota.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=fifty+shades+of+grey+3+streamingPDF 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_off0000b433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB433 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC4A 11020 bytes
SHA-256: af6b3e8bf900a66c5e93dbd70cefc7b72ef5de18b6438587e8d0d8e2cc6b7cd0
font_02_sfnt_off0000e58e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58E 19904 bytes
SHA-256: 9bf81baebae93b441294e9a72850ce96f250e1b8abd9e60af962b9b55d78f903