Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bf5b47e75401edb…

MALICIOUS

PDF

76.0 KB Created: 2021-06-28 00:09:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 04438faa9ce4c09fb7b6764178eb17d6 SHA-1: a77e7b9c0b6607f80e0d1911e09cfc1111737482 SHA-256: 9bf5b47e75401edb9dfc27fc37f850fcaa14a5033a56f8d9c41747a9ff807333
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These links likely serve as a distribution mechanism for phishing or malware, leveraging the 'formcraft' plugin's upload functionality. The document body is heavily obfuscated and unreadable, providing no direct user-facing content but confirming the file's nature as a PDF generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16096b9a69cf88---71750910797.pdf
    • https://mymango.ru/wp-content/plugins/super-forms/uploads/php/files/55c186c4a909efa9b420dd5fee5bfd51/40207013209.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d72bdf0a7---87992847558.pdf
    • http://iviltra.lt/images/files/54176579218.pdf
    • http://taiyoaquris.cn/upload/userfiles/files/20210605133350.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba51ec3c91---repepar.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160a489ed91b61---madoxoxirovix.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bf136b774ba---45006648803.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16076bd3e2d79a---sijabugemodazibuxokoz.pdf
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/0dl0qfarshm9c1oiuhug2mie60/bukalegovived.pdf
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/955ls01ve35c60uspaerpr3g8s/xovesaliviwesumep.pdf
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/fnusfe2kk3f6m99u552kv48h75/50965463535.pdf
    • http://parvazyab.net/basefile/api203/files/83451225551.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160add915dd17c---74534924139.pdf
    • http://ajivikafinance.com/userfiles/file/nozeri.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b812ebc58a5---4976350649.pdf
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/82d4c46314ca345e0bc6e985fa773cb5/rigidowedogutere.pdf
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d4c3d3740---6237570466.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/qfqoir8168gd806vujkdadd05j/kurun.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/dbj8944tclrk6tjsjr9hbn2itk/fikebepepe.pdf
    • https://mintowncoffee.net/uploads/images/files/durekuporivo.pdf
    • https://pingthye.com/userfiles/files/rakovazixigozorubaripewim.pdf
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/160825c1dcfed3---zezidatefesepatugatejo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=convert+180mm+to+inches
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c95d.bin
2a768e2a4cdae94900987560fead667cc98dc3e4ca91fa05449da9ab88550144
pdf-font-stream PDF embedded font (sfnt) at offset 0xC95D 10764 bytes
font_01_sfnt_off0000e20d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE20D 16792 bytes
font_02_sfnt_off0000fa1f.bin
cbe2e14922fc2b9f35ed08710747373b8a87b0e84cf7311bdf4bf82f2a3d9f01
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA1F 15816 bytes