Malicious PDF — malware analysis report

Static analysis result for SHA-256 366b193634643ce8…

MALICIOUS

PDF

78.1 KB Created: 2021-06-18 19:57:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 1bb96c9c522d78b150916db4651cd8e6 SHA-1: 5c47967ae27f52c379c800cab30430309b1087b6 SHA-256: 366b193634643ce80ac10901e49cbab2c7021d96129801db01beaa2133da958e
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, many of which are hosted on compromised WordPress sites. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous external URIs points towards a phishing or SEO manipulation scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=cinema+hd+keeps+buffering+on+firestick PDF link annotation
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3bce2b258b---duremedokigisolabezirib.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/1ae0387189d120884fb6702dd33f0a82/11437645054.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c77350eb576---tifimoporuxigizaz.pdfIn PDF document text
    • http://fashioneducation.ru/userfiles/file/19532998807.pdfIn PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/802c4c5b0379a6c84c2099372822d8c4/tidazanikoduxorarev.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/91114a2fab6255299ce7ac111d591a5e/87558335643.pdfIn PDF document text
    • http://firegallery.ru/img/upload/bijewokebazitafo.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/59d32c0dd57b4f24c47749b186ddb07f/gavadimefaguw.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/mefusigebedexeserebu.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16081f97c69ac2---58031737929.pdfIn PDF document text
    • http://asiancfea.org/userfiles/file/xelanukenowiwur.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/tamapaguvopamigiwisukixuv.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609443aeb2565---57607678746.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606f297b81902---wulepudumepo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/99f50b7d80bd40170402dadb2daea982/55750346798.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e97b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE97B 5644 bytes
SHA-256: 7cca036f3d0dcd168379b5a2e5fb7e51f0213b326c9d82c152d6a6e58d2117f1
font_01_sfnt_off0000fc72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC72 1800 bytes
SHA-256: 51ebeec29509b87aa858d500e37ac8853184703d07d1f913ce36d8e1dc7764c0
font_02_sfnt_off00010500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10500 10972 bytes
SHA-256: de550715729d0c73389e36d3cd84860f9f546a9f1172117f6261b9e85d912705