Malicious PDF — malware analysis report

Static analysis result for SHA-256 733f127565bcf243…

MALICIOUS

PDF

78.6 KB Created: 2021-09-15 17:19:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f0b9b867683446109f2ceb85ac1250f3 SHA-1: c847c071eeb706bc38e89dd15d49494881d25bba SHA-256: 733f127565bcf243b34cd599bec4c04adaa18c5eb142fb6d1923b7aaecfdd9ab
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings suggest it's part of a campaign leveraging compromised web infrastructure. The primary goal appears to be directing users to potentially malicious or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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://philabc.ru/uplcv?utm_term=365+days+english+subtitles+download PDF link annotation
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132db45158d1---wazibelusexub.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/87664706031.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/fugirigoji.pdfIn PDF document text
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/35783293033.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/51529616891.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/12815881085.pdfIn PDF document text
    • http://ever0036.com/assets/uploads/ckedit/files/20210904005559.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/fofofolab.pdfIn PDF document text
    • https://linkevicius.com/upload/galery/file/66139698912.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9f85d30dd---58842554304.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/71917164618.pdfIn PDF document text
    • http://isleford.com/filespath/files/20210907031608.pdfIn PDF document text
    • http://byty-pardubice.eu/UserFiles/File/vagovo.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/73525998385.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16132a76492cf7---josuvig.pdfIn PDF document text
    • https://phucatgarment.com.vn/ckfinder/userfiles/files/74334094125.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16137fa9e2ce10---divigamu.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/xotefomagolexuv.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/ritidatozivanadugadakujam.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/12710930423.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/9695087278.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/zegogigejebizemabovev.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7d71c4e8e---79089807910.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7da682b6981549045976b595997ffe9e/lejuzolisugozeresetositif.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/finobite.pdfIn PDF document text
    • 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_off0000c825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC825 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e03c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03C 11244 bytes
SHA-256: d80150d7bbd9b94dd55021566f02042e67a6b57dc981c29191e1ed4b370419dc
font_02_sfnt_off0000fa65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA65 19544 bytes
SHA-256: 0f9cd50dda0f4c308f663c69023e815f264bf89725fcfd78379a1192cae8536b