Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c85a87ace1bb9fa…

MALICIOUS

PDF

86.4 KB Created: 2021-09-18 10:57:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e2ee40d1b87f8c2bc3a4883a85f59528 SHA-1: 282c6f0ad3568a6629cc424549231e3f3477f219 SHA-256: 8c85a87ace1bb9fa9e8cfaef597365eee40bef2e8c8878d4ce272011c2b6328d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://nomylo.ru/uplcv?utm_term=best+free+vpn+for+pubg+lite+download PDF link annotation
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/refasoxibomez.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/guzevowiliweveziwe.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/47242092186.pdfIn PDF document text
    • http://peaceinsrilanka.lk/ckfinder/userfiles/files/botowuwizenifarabutaba.pdfIn PDF document text
    • http://khachsandomino.com/hinhanh_fckeditor/file/rusoxenax.pdfIn PDF document text
    • http://danguykhoidoanhnghiephp.vn/Upload/files/metamipobozuges.pdfIn PDF document text
    • https://zebcom.in/userfiles/file/92571849930.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/zefizilukenasaxudojavuzu.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9dfd9bd4e---16491724586.pdfIn PDF document text
    • http://dighakanchaninternational.com/FCKeditor/file/mejul.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/kfeqcoi0omjan7c4cfsi2s5sgq/waboli.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/60267879535.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/rikiniposefanizatagofede.pdfIn PDF document text
    • http://guchen.ru/d/files/52741787868.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/fiwenoxag.pdfIn PDF document text
    • https://sanruouvang.net/images/uploaded/file/33980188865.pdfIn PDF document text
    • https://huanghecables.com/d/files/20645443617.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/46267397129.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613258b081a4b---2375293212.pdfIn PDF document text
    • http://labellebeaute.com.hk/ckfinder/userfiles/files/sakipevokikoxitupim.pdfIn PDF document text
    • https://fotofidelity.cz/userfiles/file/78043576314.pdfIn PDF document text
    • https://needletherapy.eu/upload/file/55251876558.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_off0000eba1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA1 11120 bytes
SHA-256: a4f3c40045e155eb821051d07a05c090be9d39b37d3913505ed27e0ecd93944e
font_01_sfnt_off0001055e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1055E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D70 17800 bytes
SHA-256: a8ff96ebbe1dbc0a327ca2a8cca10958b135e47cab23f8fb275a46aa96440ebe