Malicious PDF — malware analysis report

Static analysis result for SHA-256 281fcd8ae0707eef…

MALICIOUS

PDF

95.8 KB Created: 2021-09-16 14:46:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 07d4d5e8b69506a0233f1b7e30306111 SHA-1: 81d582ac87f91a144e9b05f20c3a88f4e81abd6c SHA-256: 281fcd8ae0707eef47f18b182247074565a837a5d667f492f6f0b86f558663ed
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing a link farm pointing to potentially malicious PDF files hosted on compromised websites. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a pattern of hosting malicious content on disposable or compromised infrastructure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16138f85c7b200---13614125741.pdf
    • http://www.peritaonline.es/ckfinder/userfiles/files/gijepexalemub.pdf
    • http://train-in-japan.com/images/blog/file/39388046859.pdf
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/l1nu2o3e59nm04i2fjuvuqi6he/zazeninixogeb.pdf
    • http://youngshiny.com/userfiles/file/1631391155.pdf
    • http://chemtron-vostok.ru/media/file/mubofusenadenogaviwexope.pdf
    • http://sinners-party.de/media/file/kotuzesokuk.pdf
    • https://bibliotheque.ville.deux-montagnes.qc.ca/ckfinder/userfiles/files/soxanipigefebonukar.pdf
    • http://www.almansori-ye.com/almansorifiles/files/40421246294.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614164628f524---32032244276.pdf
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/30597954162.pdf
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/zemajevo.pdf
    • http://blccy.com/userfiles/files/fevena.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613faa6e27258---4365951569.pdf
    • http://impex-italia.it/userfiles/files/tinuboborexupuwuwamoti.pdf
    • https://agronlogistics.com/userfiles/files/62451709555.pdf
    • http://primebrokeragetx.com/ckfinder/userfiles/files/gunumobumigu.pdf
    • http://studiomanzella.com/userfiles/files/nutewej.pdf
    • http://pokebarslo.com/uploads/files/96227978931.pdf
    • http://www.bluefashion.cz/ckfinder/userfiles/files/43259202625.pdf
    • http://pensionpoint.cz/userfiles/files/winezozik.pdf
    • http://tnmetalworks.com/images/files/32916383331.pdf
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/47312784778.pdf
    • https://buddhaart.in/userfiles/file/gotefixubu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=crash+bandicoot+3+warped+download+pc
    • 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_off00010a43.bin
cbbec45e58bb9360712c76272849cf34cfdc6ace16485e289a497394a0504224
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A43 20268 bytes
font_01_sfnt_off00013f37.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F37 16792 bytes
font_02_sfnt_off0001574e.bin
9e81ada698eb5e311ec66ea421351e4d684469bab5804c8bf2d7a890627c632b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1574E 11040 bytes