Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9537af22e19a6ef…

MALICIOUS

PDF

104.2 KB Created: 2021-06-29 08:05:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 97f770f67974c756529d6f38e1b8fe63 SHA-1: 1aa711793c037fc29627ac3993b1aec64e5b4c84 SHA-256: a9537af22e19a6ef9d78e6fde3420c23425e891d7ffc0c2ff64d7893e9bf10f6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://chcial.ru/uplcv?utm_term=poor+reading+comprehension+in+adults
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c85bbb9948a---migewafu.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607424dca4f6c---78709633975.pdf
    • http://ahcxdq.com/uploads/file/04080050689.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/04695cd9a61bd439d3d19b3819f84077/79354029161.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0759fd7530---43518141230.pdf
    • https://gulyaskantin.hu/uploads/frontend/files/38481313298.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1608720e084c23---pezozavekomubajipe.pdf
    • https://larrialdiak.es/files/galeria/files/niguxixobaduzotil.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/2a712de5247310061a57fbb0980da6cf/23807626538.pdf
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/258b411ac4a445746f0255bee22e8d5f/61891429157.pdf
    • http://www.bufolari.com/public/immagini/file/94351564271.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a110e01ea77---zifipuronevuzaraj.pdf
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/08db98c0ecc95f3c3add097dec44f0ed/rutugulugipotajigiwot.pdf
    • https://airflow-skateboards.com/upload/file/zuzaxojexigujepofu.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/9b3c1ec1016b9bfa534e040920741ce3/5707894300.pdf
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/e8bcd3092968d8c8b25efc1835ca3e2c/mukokazenapavonos.pdf
    • https://gute-reise.ru/i/files/files/ratasarupisoburaworubifa.pdf
    • http://carolinaboatclub.com/userfiles/file/42892991689.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607531ab13592---12500003933.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1003d01b54---defulujowasapijiwozuxuvi.pdf
    • http://www.lugashotel.com/data/editorfile/dasozupidawudawogebigene.pdf
    • https://feng-shuiworld.com/userfiles/file/14808336212.pdf
    • http://rustproofingottawa.com/userfiles/file/73115058316.pdf
    • 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_off00013403.bin
37265b70cb46dec032a08b1be9a7adc1874ac2a3c01657b25b4ab28677fc7dc3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13403 17016 bytes
font_01_sfnt_off0001605b.bin
25fdc0ad4dc15827aaa0a10aa56b182208bdd4804ee79f6025ef6cd657efaa22
pdf-font-stream PDF embedded font (sfnt) at offset 0x1605B 11060 bytes
font_02_sfnt_off000179b4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x179B4 16792 bytes