Malicious PDF — malware analysis report

Static analysis result for SHA-256 a390bf5b3ee22c81…

MALICIOUS

PDF

74.9 KB Created: 2021-09-20 02:32:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c6cfb2896e0031611bd9117a7232178f SHA-1: 5426ec2623b16ee99cced6e4ddc23f5951a4cf07 SHA-256: a390bf5b3ee22c8166afa9ffea2010e0ca09c79347e053bbe994cdcd4be9276f
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated, suggesting an attempt to hide its true malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://irlanc.ru/uplcv?utm_term=best+video+camera+app+for+android+with+filters PDF link annotation
    • http://eshop-kocicinadeje.cz/files/file/fezirusiteretibidugulebom.pdfIn PDF document text
    • http://guides2alpes.org/uploads/file/18258860630.pdfIn PDF document text
    • http://klimatyzacjaradom.pl/userfiles/file/larewubifilixibakorova.pdfIn PDF document text
    • http://ramenzoni.eu/userfiles/files/dojipafiwemin.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/64863259323.pdfIn PDF document text
    • https://full-e.com/app/webroot/userfiles/files/20210920_054747.pdfIn PDF document text
    • http://hingliltd.com/userfiles/vijunaludozugazukib.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/buxetusajexujogiba.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/b8pilka1ravh3lnkvtp8taaeaj/fabemirekopofi.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161470add9b85d---31105964277.pdfIn PDF document text
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/zitekaxorivilujovon.pdfIn PDF document text
    • http://rayer.cn/d/files/muvapumobemulop.pdfIn PDF document text
    • http://dpsnowodworze.pl/userfiles/file/78636609601.pdfIn PDF document text
    • https://thietbidiensino.vn/media/ftp/file/wurisamimazuvarewujolad.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/fipipidexajefeg.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/gafuxif.pdfIn PDF document text
    • http://ferrogep99.hu/static/media/file/sifuzovufarokukunomu.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6d6d15467---88281296861.pdfIn PDF document text
    • http://pololanna.com/user_img/files/tojotebutofam.pdfIn PDF document text
    • http://fruitvita.com/files/files/41643860081.pdfIn PDF document text
    • http://viprealestatebrokers.com/userfiles/files/8089063594.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/rijato.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_off0000bdff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDFF 11092 bytes
SHA-256: d56a9737f5cd27e032f5f30e4285e4ff7795589105fca4fdea1e098e3c535b80
font_01_sfnt_off0000d7bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BB 17700 bytes
SHA-256: 97c7d4c4aeec12cfc792a5cc7f76b1ee108f8716cbcad6821e5b791c582102a7
font_02_sfnt_off00010592.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10592 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1