Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f1876ad5e410b83…

MALICIOUS

PDF

73.6 KB Created: 2021-09-08 11:15:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8f671e2ab458cdc549ad38dfa6f5566f SHA-1: 90dd145b03103a12cc462156a558bb02728982ce SHA-256: 3f1876ad5e410b8351834980b364722da271aae8b4c4d4dcddb4ed3be4b76829
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted from this sample, but the URL structure and heuristic firings are sufficient to infer a phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=facom+expert+catalogue+pdf PDF link annotation
    • https://rowadalbyt.com/userfiles/files/zasozu.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/fpjmvu02qmvdculsha8hosjo63/95486056270.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/rutis.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/32799761289.pdfIn PDF document text
    • http://jumpstart.mobi/ckfinder/userfiles/files/lekatukumabelu.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/f78c8464ecf5a4147c956daa173de9f7/wotapopiwivikenewat.pdfIn PDF document text
    • http://apsons.eu/files/file/55519870950.pdfIn PDF document text
    • https://www.herewardcarpets.co.uk/wp-content/plugins/super-forms/uploads/php/files/0u1o44it27dio4l4ssom5ega44/47437102061.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/vegilusigexujifepobazukil.pdfIn PDF document text
    • http://coalcreekcentenary.com/clients/5/52/52f735e63eff8706e1a2a73a20aef632/File/gimuzijazim.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/22538282156.pdfIn PDF document text
    • http://ogledalata.bg/uploads/pages/files/fosekukejur.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160f80540c50aa---26880620095.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/c91882629cfcd7424b280b71d0c2ee9d/pofifurivasidat.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/39058771192.pdfIn PDF document text
    • http://dabbleanddesign.com/clients/c/c6/c60e280709801842a26e47e23f21f170/File/zagegetujisabepunesesimiv.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c7bdbe477---famogakaj.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075df72754eb---rewukese.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/zunaxaxun.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/78215204571.pdfIn PDF document text
    • https://bdcomunicazione.it/file/92462113915.pdfIn PDF document text
    • http://www.golfusa.be/userfiles/files/dikevikowe.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/jakadivuka.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613515aa53792---wanofirukimononataxesad.pdfIn PDF document text
    • http://xn--h49avwqct32ewe967crscpsaz7d.com/ckupload/files/57212075612.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_off0000bc9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC9B 10776 bytes
SHA-256: a2e53220c1ee1e33bdf445cd5f0ad74de602d32d90a802986e0533951caec5aa
font_01_sfnt_off0000d544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD544 16536 bytes
SHA-256: 25aeae2b1c78043f42e4cd97ac7b73afef31a38a1601e5cc72e6fdb500355ff2
font_02_sfnt_off00010058.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10058 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1