Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c61d4fff6c8147c…

MALICIOUS

PDF

88.5 KB Created: 2021-08-29 09:37:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: aec55a0fd38b277d4d8f0105668b5f5a SHA-1: 08a5830e6454a5601b572a47a9578db143badc81 SHA-256: 3c61d4fff6c8147ce7943cceeb33a4033161818718ae33246135fef56b70e97d
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 compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO poisoning or directing users to phishing sites. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://eros-arena.com/eros/userfiles/file/72835592220.pdf In PDF document text
    • http://dagmare.de/userfiles/file/jeron.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/2222679836.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c276a940199---duzitejizisupizufujuvekal.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/884d93d2d2cf65aadab42692460addb5/nazijurixubinod.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/mac9fvmtohab5tabshce9940fh/jurafelaxasi.pdfIn PDF document text
    • http://fratellilongoni.com/userfiles/files/99368751709.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b87d0b081e---movir.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/43070590019.pdfIn PDF document text
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210725_121254.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/solorav.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8e2b74ff3---lijolufemarumupud.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/95396128432.pdfIn PDF document text
    • http://tw-jia.com/uploads//files/202108131933329889.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/wafim.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/4bbcca76c41d55bb7fcc605b046f209f/43535977891.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c97030ce784---nokadu.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/rafaxudasab.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/62537214138.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/zagimafesomuki.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/daa55b5234f6235147d32642b2b56f70/1424235879.pdfIn PDF document text
    • http://farashimirooz.com/files/67567069175.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/zunizax.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/c923ff16283d62c0865517c6a94e88fe/faledukemivom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=what+does+mean+archivePDF 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_off0000f360.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF360 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B77 10648 bytes
SHA-256: 539bd92546bda0a8518312cf1e4bb999dd9b7880627c041f4772da6eab0bb2b3
font_02_sfnt_off000123b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123B1 18656 bytes
SHA-256: 78b553ccc977d85b5e684056e4a53d741d52e2086bcf7ec58c8a36b2592e11e3