Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5d73594b2280352…

MALICIOUS

PDF

74.1 KB Created: 2021-09-21 04:16:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f9e1ae1ed1dae4ac7bdb8a4ac0100d27 SHA-1: d1be58e7d29fcf4cdb08eba580b4a01e1202ecac SHA-256: d5d73594b22803523f142575554c7b832bbbaba5f68a3ab5413bb4e10a7f425f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm with numerous external URIs pointing to disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated, but the presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly indicate the document's purpose is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://synerhu.ru/uplcv?utm_term=bug+android+11 PDF link annotation
    • http://scvumaichiramen.com/uploads/files/4206643283.pdfIn PDF document text
    • http://ziconiavip.com/uploadfck/file/65213862286.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202109200515156354.pdfIn PDF document text
    • https://dalnoboy.com/data/filestorage/upload/files/78559597628.pdfIn PDF document text
    • http://maimungkorn.com/UserFiles/file/zeduxexugiwovaxivanefo.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/xebukusexa.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/84719605624.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/vituzul.pdfIn PDF document text
    • http://gysanya.com/upload/file/210921013416193295mdck8adsjo2e.pdfIn PDF document text
    • https://lawweb.info/mycms/admin/userfiles/file/4319361250.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/437b11fbc701ab1d5d71faf259c20758/xolirilipaviguwosuzez.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/rinosivo.pdfIn PDF document text
    • http://zatuchlina.cz/upload/file/98917910590.pdfIn PDF document text
    • http://atrsara.ir/resource/files/lafijasujiwiludojumezew.pdfIn PDF document text
    • https://www.andreivieru.com/ckfinder/userfiles/files/buralorivixudovowidure.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/felijipo.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/jurizugop.pdfIn PDF document text
    • http://auto-rad.pl/userfiles/file/30065313963.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/49849776546.pdfIn PDF document text
    • http://everintelconsulting.com/upload/file/202109161919448199.pdfIn PDF document text
    • https://booburger.myagenda.cz/pictures/editor/files/podavuzebamewusimugizub.pdfIn PDF document text
    • http://sfalojistik.com/userfiles/file/todawisali.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613383e3f3b26---mukabaxovejizobolutef.pdfIn PDF document text
    • http://remproekt-m.ru/admin/ckfinder/userfiles/files/luzuzogo.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_off0000c1ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1AE 10184 bytes
SHA-256: 4ba854cf926629b66b3ca301377ba1cb60502d6f121ae4b7e2ac1a9a7642486e
font_01_sfnt_off0000d85c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85C 16712 bytes
SHA-256: 42261b8dfb526bf624e3f9bf9959cdc8e1fc9658743c2a2393a179c61abaaab3
font_02_sfnt_off0001037f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1037F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1