Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b4e2ec86a8d319…

MALICIOUS

PDF

76.4 KB Created: 2021-07-05 13:36:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fbd35d37f3e9e42fca95f89deba318a3 SHA-1: c5b4f195a4e8f7dfb16e5087220f7e44d34ceac1 SHA-256: 91b4e2ec86a8d3192b758810102a0f83b4a161000cb2d052efc661bf60d0e090
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple potentially compromised WordPress upload directories and other unknown hosts. The presence of numerous links on disposable hosting suggests an attempt to obscure the true destination or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078286de9a44---nawugatubudufuvogubij.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/bcf57b0168fc524675d02152507b72eb/dubagomalezumabusi.pdf
    • http://ellenia3.eu/userfiles/files/segikaperid.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1607163bb0154c---refaxema.pdf
    • https://hotel-la-licorne.fr/userfiles/file/74149556972.pdf
    • http://koszyczarek.pl/userfiles/file/lonum.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/872a8822c6bd1e14172154bf04f48086/90804397433.pdf
    • https://people11people.gr/uploads/File/zafobewewe.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f34d28acbe---wuzepilozuzatopowo.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/71tat8urm1meihajlbk5nfb750/xutipa.pdf
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/b4c87b331fdb534f09477595fa09e9bf/wesozazopimiz.pdf
    • http://elyriahigh1974.org/clients/0/05/052ab20d644b737728595af1a47b4450/File/gipajixabezanasevopigipar.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0f39355e13---guwezanudefar.pdf
    • http://smit-electronic.hr/upload/datoteke/rudagiritejow.pdf
    • http://biotop-zamosc.pl/userfiles/file/9328814465.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfe715c027---gigotexufaviruxiwitew.pdf
    • https://m3csrl.com/file/bowixugo.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/64017597775.pdf
    • http://www.prieteniitehnicii.ro/documente/file/gometeju.pdf
    • https://ancoraeducacion.com/images/85427071720.pdf
    • http://pokemom2.com/uploads/files/mikegifetesesed.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160738a2d65921---92184385788.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/0617b36c7b6a33bcd151e99e0d7b27a9/xuzafab.pdf
    • http://benetworkingpro.com/ckfinder/userfiles/files/dajafekenulabenebo.pdf
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/36024c84f016f2542f0ec5b273d51523/9401111892.pdf
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/c6f02786329a721f76e831674096aaf6/80990882369.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=difiore%27s+atlas+of+histology+with+functional+correlations
    • 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_off0000c5cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC5CF 16792 bytes
font_01_sfnt_off0000dde6.bin
0cd05546c822c6fa3afd28a53826ee6451a344059917152e6f162f87ce5cf564
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDE6 10952 bytes
font_02_sfnt_off0000f75c.bin
1639535b438a3a411ad41a858986e1f6132a71365b0fc807bac2d49d3c1d7fb0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF75C 16888 bytes