Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5728b9eb4238d01…

MALICIOUS

PDF

75.6 KB Created: 2021-09-16 15:01:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2f36dae20433d78a30d5103daa71d306 SHA-1: 31c6e58066f567a08a27823fc1c6349f77709063 SHA-256: a5728b9eb4238d01b3cb1450e2366a7077e5487cb57ac22a2f5e17baa076fc47
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites or disposable hosting. The presence of these links suggests the document is intended to lure users to malicious websites, likely for phishing or to download further malware. No scripts were extracted, but the structure indicates a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://chcial.ru/uplcv?utm_term=ko+player+2.0 PDF link annotation
    • http://akinmedical.com/uploads/file/dodarodajanowebixowirajoz.pdfIn PDF document text
    • https://landi-bg.com/images/file/70362836734.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6f2f54547---sodusuz.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/guvusituxex.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421e3bc1c67---kepowegivimo.pdfIn PDF document text
    • https://agri-mal.pl/userfiles/file/fejopotikolinugir.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/54671430907.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/nbn6bs3l0v01sh0akob5a4sqd2/jozarofunedibojikedu.pdfIn PDF document text
    • http://xecuoihuyhoang.com/uploads/userfiles/file/kitokijogorak.pdfIn PDF document text
    • http://smart-ventures.ch/upload/Editor_Images/files/sagutunigavigawebi.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/87031313276.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/ahbk2fr0lnab01qahjauisegnn/58790935211.pdfIn PDF document text
    • http://medicom.pl/userfiles/file/52357888601.pdfIn PDF document text
    • http://ifa-astrologie.de/userfiles/file/34795417358.pdfIn PDF document text
    • http://agrocare.hu/ckfinder/userfiles/files/kafopuladedamegug.pdfIn PDF document text
    • http://swhos.com/upload/files/piwakusagowadad.pdfIn PDF document text
    • http://dreamcatcherltd.com/userfiles/file/rirebuwuwoxuxat.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210910101318244936102.pdfIn PDF document text
    • http://midel.me/userfiles/file/7183602196.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_off0000c1bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1BC 18388 bytes
SHA-256: 2d47633ecae26fa1cce23af9f3c69d1ada8126e6b78b4d03d24a55191d591a3e
font_01_sfnt_off0000f247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF247 10196 bytes
SHA-256: ffab666a3fb1c35f2067d36273013c474737766c4af2801372666bb997856046
font_02_sfnt_off00010959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10959 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1