Malicious PDF — malware analysis report

Static analysis result for SHA-256 7e89f5afafe075c7…

MALICIOUS

PDF

82.0 KB Created: 2021-10-05 03:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 71dc9485bdbbb899d00deeb1ec6d1a19 SHA-1: 539a75277759be1c040ad8fddfb06ceec091fb48 SHA-256: 7e89f5afafe075c77d6c4f709f97e53e3e382f4c87ad1fa0533f898e4ced6ab0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF 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 URLs pointing to external sites, some hosted on compromised CMS platforms. The `wkhtmltopdf` authoring application suggests it may have been generated programmatically to serve as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://oniceh.ru/uplcv?utm_term=forever+stamp+weight+limit PDF link annotation
    • https://ms01bet.net/contents/files/tikudi.pdfIn PDF document text
    • http://sangiorgioautoservizi.com/userfiles/files/vebubedarod.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/82134324096.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/lakiramasamalopixevabovuf.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/22770212753.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0343d3481---buravuvufek.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/xunokasidokus.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/detomopuditavuwiweguk.pdfIn PDF document text
    • https://pielinks.com/UserFiles/file/wozavowus.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d94aa0ab15---jobetevemototopavuripef.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153b7eb8e7d0---83165207489.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/gepuzi.pdfIn PDF document text
    • http://imbirimbir.ru/files/boledufok.pdfIn PDF document text
    • http://jump360.co/upload/files/20210901160614.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/20913043241.pdfIn PDF document text
    • http://lanaecoloridabruzzo.it/userfiles/file/38400675167.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/4ut3stqs5lrg4vltcorpnl0val/44163186386.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/7k2q79ipeco5dkl28pmvtmuejf/7332236399.pdfIn PDF document text
    • https://kinohorror.com/upload/file/43962995862.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/d673b6bc44bddc642d1eb8cf5844e292/50919151727.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/wolizagavapi.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/nurur.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/72305092751.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/16737522903.pdfIn PDF document text
    • http://dainichiji.com/upload_ckr/files/jeponusunimi.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_off0000d792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD792 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA9 10724 bytes
SHA-256: 95403c3cd279d6e4500ad655aec9dc79269f26df0262e2b29b8b0b34ac0f3e29
font_02_sfnt_off0001085a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1085A 19224 bytes
SHA-256: e82fe7eff0987cbd5f5a560f0078d5b79151c0516a49a5d5a6349f8330aeeaab