Malicious PDF — malware analysis report

Static analysis result for SHA-256 d421a8eda9721481…

MALICIOUS

PDF

86.6 KB Created: 2021-07-05 17:46:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 4876025503fe576340d79159d5adc546 SHA-1: 1c7f0463f34da69d071d2ca6d8b04277c98b6800 SHA-256: d421a8eda9721481bdf72e436149d664593949e988c62ece3fc82a4f2f6aa4ec
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also contains numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vankouwenenmastop.nl/UserFiles/file/8404788527.pdf In PDF document text
    • https://novahealthclinic.ca/userfiles/file/feperakexoraxizo.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/062325499676.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/nusafetakoxadijenikuko.pdfIn PDF document text
    • http://sam-global.info/files/file/97168453858.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/r7c5dc3b4g2ol51lrmf8q5a237/69824371122.pdfIn PDF document text
    • http://hopkinshigh62.com/clients/7/77/7764523e397120ad9b09b1da26998858/File/rowebabe.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/0e0ce94c6d39a460d5fa1df1046f4bef/36441805474.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/4t0d4aogne5hi5no701lgqgme2/velijavazamonotebininabu.pdfIn PDF document text
    • https://flvirginia.com/wp-content/plugins/super-forms/uploads/php/files/e88cab18964bbf1991d92e5c2e49059c/9337608204.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096bc169b1b7---xokesijifatiweve.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16093d009b5e20---fizuwativivin.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/wilatikununadisotis.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/sagadakamos.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc8c463029---50866251086.pdfIn PDF document text
    • https://ndmoyun.com/calisma2/files/uploads/91810337863.pdfIn PDF document text
    • http://kurumakaitori-one.com/js/upload/files/tunoxezowopoxasefof.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/af7a4b862136bd8be31c022bf634aeaf/lagowewonu.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/rumekopilokow.pdfIn PDF document text
    • http://bocghebinhduong.com/media/ftp/file/64045022464.pdfIn PDF document text
    • https://szekszardportal.hu/userfiles/file/lavijizapufevo.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddf18164c09---39127389683.pdfIn PDF document text
    • http://dharmapremipariwar.org/userfiles/file/toveme.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/ruzukasi.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/lenakedimakafol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=melt+ice+on+driveway+without+saltPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED20 10824 bytes
SHA-256: ae7f997f61c8296ff241c2b5402f765d0dc30763fce29c9729f88fbce31e1a74
font_01_sfnt_off00010623.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10623 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E35 17212 bytes
SHA-256: 276b0a91b3c949295a30511a8334adf7e251da3701ec89dfd13ad0306b3f1e0e