Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3c1da662a5b6c15…

MALICIOUS

PDF

86.1 KB Created: 2021-07-12 22:57:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-22
MD5: 44e565ae9a45f989c1a6ee6648b5c416 SHA-1: 4ddd8175547d448a00536b45d6ee636b29f2aedd SHA-256: a3c1da662a5b6c15168bca3d2abc5ca63be4175a0d6e92fb60f93c5410191aaa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160734b5fddb58---63128976422.pdf In PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/9e54eda5da64622b2df6b92d231e25c8/62626447417.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093e262601aa---dovatigax.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8dcf9dc84---kotononi.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bce098ed040---53033407662.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a3cd3a74ec9---zadevukanukalevagufomolu.pdfIn PDF document text
    • https://atlastoursntravels.com/userfiles/file/razomikafabojusese.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a86acc433f5---fukukefojazugemo.pdfIn PDF document text
    • http://healhumanity.foundation/userfiles/file/bapuvafarabewujetofe.pdfIn PDF document text
    • https://shreenathtechnologies.com/userfiles/file/80073628672.pdfIn PDF document text
    • http://bigsvatcharasith.com/userfiles/file/tokomawofopaxuzoxov.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/fc4a356f08b0b443cc5abe154efa3ce0/bawomofume.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/99c406edc14464558a563fc0325882a1/87884333927.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/0ff85e8610612ca6c525f7f322c8238a/59333254699.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/35416282960.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607721f874912---38369819090.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/joxuxakazoza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=the+gouldian+finchPDF 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_off0000ef26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10738 17240 bytes
SHA-256: 4cf82412b10c56e7213c33eece75fa7ef491cfdd26408fcc15fac9eb4e9bc672
font_02_sfnt_off0001349c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1349C 10452 bytes
SHA-256: 4c92f876e86e3303bb9ed8c47ad6f0cb6cbd3e9ab7e584312a9d93238a1a5beb