Malicious PDF — malware analysis report

Static analysis result for SHA-256 a22bcd63b7c46375…

MALICIOUS

PDF

86.7 KB Created: 2021-06-28 17:13:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 763a303be2a8ea6ba1435b76fd78b53c SHA-1: c5c1b09616da05d76e1fa8ebba3413db932da393 SHA-256: a22bcd63b7c46375447392ecbc6d933257d16b322a6d28547d868ce691fb752b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of a link farm hosted on compromised WordPress sites, with numerous distinct hosts and URLs pointing to PDF files. While no scripts were explicitly extracted, the nature of the link farm suggests an attempt to redirect users to malicious or phishing content, likely initiated by a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://sosnovgeo.ru/userfiles/file/76115802282.pdf
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/c093654d1ed6e399b66f21f6e455e2ef/3377657526.pdf
    • http://hotelbelleepoque.bg/userfiles/file/buvusipizosa.pdf
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a160b182aa8---guloberotesavudomufo.pdf
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a2fecb335---xepikiparavawi.pdf
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c04d6099d75---24654530303.pdf
    • http://caigeshi.com/uploadfile/file/2021062100532173499.pdf
    • http://ghioroiu.ro/sites/default/files/file/puzireduxutujidunezap.pdf
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/ne6v6bks8f1jq5pd23g3pmo7sn/bosufukomamifixas.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/b0hc4vh2ivj67rj3mcq195p1p7/31029144445.pdf
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2110b028ac---33727979420.pdf
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608befd3b8316---tuzezuvi.pdf
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/4401077192.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077d8bcc0c06---vegawanolodonimikuvokeni.pdf
    • https://transit-connection.com/userfiles/files/gikaxot.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed14b18011---vatefamegaw.pdf
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/961e42794939295b482677fa0ca5811b/4940918387.pdf
    • https://swagath.co/new/ckfinder/userfiles/files/noxumofaxonudojuna.pdf
    • http://czdashan.cn/uploadfile/file/2021042822340273499.pdf
    • http://lycee-elm.org/userfiles/file/fetemefo.pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160705b4dea967---kepub.pdf
    • http://4grd.com/cmsimages/file/busakijuwimomanigexetutig.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab10f5d9b4---18394725947.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/d3i1a12e6lfltv9j7srqdg16ng/21245621094.pdf
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/rsu1403ni7vi0jqshm3fv81mg7/kisuf.pdf
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/b19a780d76e094192586f21d16c72802/57387536331.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=central+lymphoid+tissue
    • 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_off0000ef47.bin
f7e1596ad7a9ae3b54f99b6aae4acec3058fcefe73871f35aba1c3b283d0dce8
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF47 16704 bytes
font_01_sfnt_off00011ade.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ADE 16792 bytes
font_02_sfnt_off000132f5.bin
5f75f8971a895f39916ae267ad6c3ea7c09525c3fd1942a6ddd6963c2171aa52
pdf-font-stream PDF embedded font (sfnt) at offset 0x132F5 10904 bytes