Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fd8e92ab9d3e8ff…

MALICIOUS

PDF

81.3 KB Created: 2021-09-12 15:46:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d8a97cad6cbfaf4d5c44e55fd5dc72f4 SHA-1: ed1824773692edab7cb26b1a002391c68af58ac5 SHA-256: 8fd8e92ab9d3e8ff8a8ef7559dfc7ef5460f49cbd363dd563a0c2a6ed6581557
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these links.

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://ketchas.ru/uplcv?utm_term=vue+js+bootstrap PDF link annotation
    • http://monterroso-construpuntos.com/campannas/file/pusofojowuvazelaf.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/21090802004480679158mx0.pdfIn PDF document text
    • http://www.klimavill.com/data/editorfile/legowasojaxigexab.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/bizolen.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/kulefejinuride.pdfIn PDF document text
    • https://vilnius.cvzona.lt/resources/img/files/54165301343.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/zigofagaka.pdfIn PDF document text
    • http://aiaato.com/FileData/ckfinder/files/20210909_B3599C9A0B487AEA.pdfIn PDF document text
    • http://synfarm.com/upload/files/83897345600.pdfIn PDF document text
    • https://highrise.pl/file/63796777458.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134378320b8e---83033936559.pdfIn PDF document text
    • https://bandotrading.it/uploads/file/nanuze.pdfIn PDF document text
    • http://clerus.hu/files/file/rivenabinopejulewomob.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/buluwufo.pdfIn PDF document text
    • https://ww150006.linebot.net/upfile/files/20210901114917.pdfIn PDF document text
    • https://permargi.com/files/galeria/files/domaji.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2d85caecb---22190143274.pdfIn PDF document text
    • http://nenorm.com/files/files/22339064711.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/65456957379.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/pozefosol.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/jajivegexesukibinuru.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/sejabevarifuxatamanoruv.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137fb636dbd1---6273680061.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/mojatazud.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_off0000d099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD099 21104 bytes
SHA-256: 2bd542886f2fa2b2742b2e707b199a737c815cf9c717abd7e97126cdbbf8f63e
font_01_sfnt_off0001084e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1084E 10340 bytes
SHA-256: 1c1a6eb9fba07a4a0aaf0ffceeee71f04fcbcb08d744ed8b6877223c085898b3
font_02_sfnt_off00011fa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1