Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ec051cbe5108211…

MALICIOUS

PDF

86.4 KB Created: 2021-06-25 19:44:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 916a8e92155c6210ff668d4ce9a7da25 SHA-1: ee07df4813325f36cda47fc274720969bdd87e61 SHA-256: 4ec051cbe510821119644ee4eace0064eedc58c9c0a41771a8680e77d4340156
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, specifically within form upload directories, suggesting a link farm designed to distribute further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct textual clues, but the heuristic firings are sufficient to infer the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b55f09b39---pomemawalawuromujositojak.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160749dbeb44ec---9243751065.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609b727709eb6---pojetijebixulu.pdf
    • http://andreaslasnik.com/data/files/jegudewuri.pdf
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/20lr57s06ammqlcustrleppnt7/tusowobu.pdf
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/cgrihl6l2qj8mqb2gpkkqj9qov/xivazejujuteg.pdf
    • https://etonbio.com/newsLetters/images/file/mowelubezivibenefo.pdf
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/1vu2m2lnsjotuq65gted7kv1bn/69816126684.pdf
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/07f1ae04419da854d1cce8ad0fa67d4d/32302605774.pdf
    • https://soechi.id/userfiles/file/sifulam.pdf
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/cac5cdf53a0bc1fe179e0661f5ea2536/48890192926.pdf
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/4jl5utq8se6embad49vqaifbeq/rogemepafumodekuvuki.pdf
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/0d58a4e3460b773847e469f63934434e/24156482555.pdf
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2b58b9a74f---losarazelekakuzavom.pdf
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/f8cuq9c2pvbmsuurigv6ll0m94/bopetef.pdf
    • https://manuscripthandler.com/userfiles/file/ritetuvene.pdf
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc53c787bc---leseduvalaruvo.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/fdac22b30a8a168f6527176a8e88b80a/40608177116.pdf
    • http://kondicionery-lubertsy.ru/upload_picture/file/gawobipelemalufigopijebe.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160c55ebce3839---52068743984.pdf
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088007494a32---8216451097.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160773b3a6dda1---72515547557.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f61eb2426---14486261726.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/e5fe121e500c17151b7456847afcbdff/84398130319.pdf
    • http://work4shop.cz/userfiles/file/gefab.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=unswaddle+baby+for+night+feedings
    • 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_off0000edb6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB6 16792 bytes
font_01_sfnt_off000105c8.bin
956209c8067442e3725665b8968e5294cf9d59f86a4e311a60044a1831e26452
pdf-font-stream PDF embedded font (sfnt) at offset 0x105C8 16832 bytes
font_02_sfnt_off00013157.bin
3c2fd92b7b7f350765ab928dfbf5cc0ec6301e0a751f519549b0ea1a6c0ecc67
pdf-font-stream PDF embedded font (sfnt) at offset 0x13157 10980 bytes