Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b7e81457ca20430…

MALICIOUS

PDF

80.9 KB Created: 2021-09-08 06:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0922a8f8614b4d3c24ba072c4cabb7e9 SHA-1: fc1585c7fbb4b369a3a6553749d55a49dcf7f1ba SHA-256: 4b7e81457ca20430abe20f97cc4c22d8fc02d423fde4ac874150eaf5504bc280
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristics point towards a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://wastran.ru/uplcv?utm_term=la+serpe+jaenada+pdf PDF link annotation
    • https://grandplaza.bg/uploads/assets/file/66699278054.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160888fbf380aa---67446565433.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a30a1ab9a---69997488647.pdfIn PDF document text
    • http://groupementpecheduloir.com/ckfinder/userfiles/files/tuzer.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee8b6a5260---wexizamitodukuledaj.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/90095607444.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/b78d902a8b34405ead7b6b691acc9141/furonobu.pdfIn PDF document text
    • http://fitviewer.biz/files/file/70448066863.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/64332416847.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/34099229942.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/96746830036.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/0f4fbde74ac8c2d4311e5af0d21d04be/jotaxakavuxigutixiwi.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3dece1bc9---55374478783.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/d84cf97fafefa7d0b711209f515a9e8e/71615435854.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16104d87722cde---mavesitoji.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e02d3c57583---lorajaz.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/kitabulaxixuposusuz.pdfIn PDF document text
    • https://isleo.com/i_photos/file/93702228983.pdfIn PDF document text
    • http://classicalgardenfountains.com/uplds/file/76297451794.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e3e36b33e8b---xejepa.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e587cac5ba7---11679894621.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16105e3351123d---84750527553.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/ziripinexisaduwulise.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/52670701754.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/5s9ofqhfltionto05olafhe7qa/madinujegit.pdfIn PDF document text
    • http://mousike.it/img_ins/files/82457853522.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_off0000d5d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ede9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE9 18856 bytes
SHA-256: ecbe0915f40bf1810796281c12797f834d0c908099bed603a0264536376737ba
font_02_sfnt_off00011dc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC6 10224 bytes
SHA-256: aae41a9454b5879d4078db48b907d4e289b19e3c68373fc4b05aac4969e74bbd