Malicious PDF — malware analysis report

Static analysis result for SHA-256 f24cb1db9d31141c…

MALICIOUS

PDF

87.0 KB Created: 2021-07-03 07:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6a1ed402562ab4389b8c532f4746c725 SHA-1: 84dad06c6ecb4251ba91c87f537e91d58666b4db SHA-256: f24cb1db9d31141cc640088c4ffc5add21286c044185a1b0862431b835ba04cf
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/iepp3t8b3slu048bg9d4acm32o/66333428172.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/kre43fo83cjbfpubjdqnnfv87c/babulo.pdf
    • https://laetitiabernard.fr/images/file/fonugizaketukezupetufugub.pdf
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/b4826ad1a7ebd6b1f24253272a35bf9c/dizepodidalijumadiva.pdf
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/78678471953.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d826ed2934e---wadugivop.pdf
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160711c0dbb092---rilajub.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d240050689---petabepenarusawatu.pdf
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/3c61e8632dbe9aa7e05a8b99f19ed416/56429614144.pdf
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/8135267bb143931c62083b67775f62c1/nonezuwupipebezerolilelu.pdf
    • https://arte-salon.ru/upload_picture/mezojodozo.pdf
    • http://alexanderjamesbackcatalogue.com/userfiles/file/sowoniwisiladono.pdf
    • http://learnersdigest.org/userfiles/file/30902728751.pdf
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/43d4f1b1d894cb9a0647e530c3bc7e5b/zuzobipulisuzuz.pdf
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160da487c343ac---zovosavidaralusuvox.pdf
    • https://kimtuong.vn/isc/public/files/fckupload/file/bunezomotaraw.pdf
    • http://dzbnf.com/upload/file///muwexum.pdf
    • http://stacjaregeneracja.pl/userfiles/file/80705379777.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9bc27d764---feguwenij.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/cdadf506460f4884b5beadb9cea383e2/21434381151.pdf
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be42496da36---78857107931.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=7th+class+english+chapter+2+question+answer
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db99.bin
00b1f632e8afe72716c8bcdb76b7901b56c060d1dc0f96f3f5c1b8373b85735b
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB99 16140 bytes
font_01_sfnt_off0000f111.bin
3cfec0aa70c1e32f85daf1365ef2bffb8e75d8148e4860a239abac2b2bee6ecc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF111 16832 bytes
font_02_sfnt_off00011ca6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA6 16792 bytes
font_03_sfnt_off000134bd.bin
27daeec8904cbf344a1b95981adeca75a97dba42a263b02824241b389e7cff64
pdf-font-stream PDF embedded font (sfnt) at offset 0x134BD 11060 bytes