Malicious PDF — malware analysis report

Static analysis result for SHA-256 adb10c2113b0c8c1…

MALICIOUS

PDF

84.4 KB Created: 2021-09-24 09:08:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: db5edbf531d125700bc924660c86ddf4 SHA-1: b0bb4954261c9965607315c86c01f5c2f7b8e6fa SHA-256: adb10c2113b0c8c15ebbfe01919cad943d6e8350c55f4b8c2ecece3fa02dbf09
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a large number of embedded URLs, many of which point to disposable hosting and utilize UTM parameters, indicating a link farm designed to redirect users to potentially malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies this pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://catamma.ru/uplcv?utm_term=111+222+angel+numbers PDF link annotation
    • https://studiecarriere.it/uploads/file/sagiwivexizozuguk.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/rivutawo.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109171818445749.pdfIn PDF document text
    • https://digireg.es/upload/gebawezijolepi.pdfIn PDF document text
    • https://telorgabus.com/contents/files/542129010.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/8694787004.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/nikujopag.pdfIn PDF document text
    • https://exam11.menapoint.com/app/webroot/upload/files/narab.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/nimixefurepazuf.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/80557319730.pdfIn PDF document text
    • http://duplisite.com/userfiles/file/tebafimadojerilolevusuxil.pdfIn PDF document text
    • http://konberdbio.com/upload/files/50509572694.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/vedofipusosizimaxudavezij.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/32263503523.pdfIn PDF document text
    • https://ngonluathan.vn/images/ckeditor/files/3788012961.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109010601186592.pdfIn PDF document text
    • http://ipost.mn/ckfinder/userfiles/files/28101180112.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b633ebcf46---43248547883.pdfIn PDF document text
    • http://dar-tom.pl/userfiles/file/4401898782.pdfIn PDF document text
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/76831982296.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/moramugabu.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/57592885424.pdfIn PDF document text
    • http://srilakshmienterprises.net/uploads/24549933998.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_off0000e7ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7EA 17208 bytes
SHA-256: 507624ec7c0f36c8add65a6adcd2e8bb15d9cc72ce3ae4fd0db601bf7afa78bc
font_01_sfnt_off0001140f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1140F 10456 bytes
SHA-256: cf7f1334919801263b606d1cf980cbb85dca4e10e2c724d3d7611b9fb1f22986
font_02_sfnt_off00012bda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1