Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe23041a7fafe2b5…

MALICIOUS

PDF

80.7 KB Created: 2021-09-20 21:49:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 81bcebe604ade6c696d0e0a39d80b739 SHA-1: ffc8414be925a23515aaf81b4b37e178b7243bb7 SHA-256: fe23041a7fafe2b56bf159b3f04bd242012a8dcd92fc2f3151246b0d8aee8598
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is flagged as a link farm pointing to potentially compromised WordPress upload storage and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through the linked PDFs. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://archism.ru/uplcv?utm_term=custom+rom+building+guide PDF link annotation
    • https://kompaspt2.com/contents/files/bivepuzatapode.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/duruvuzumaburixaparape.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/xoborobiganewilojijotol.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/49184585192.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/37012691429.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/somutebazaxusekapu.pdfIn PDF document text
    • http://dlzj.net/upload/files/20210919025036471425.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/tekaloginelotidafiv.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1c7189995---55951706841.pdfIn PDF document text
    • http://www.vako.vn/app/webroot/uploads/files/vazenofuwupuludejexuku.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efc18bd378---86689294021.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/23fbbba6549c01c1676f423500996a8c/warenuxulorola.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/5255725268.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdccf3d61e---27055438395.pdfIn PDF document text
    • http://herium.net/FileData/ckfinder/files/20210916_1165A9FA76CD96E6.pdfIn PDF document text
    • https://vleek.com/uploads/files/36573976923.pdfIn PDF document text
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/702045133.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/zixifaxapezulejodosuri.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/96189975537.pdfIn PDF document text
    • http://vanprodukt.cz/UserFiles/File/gemaden.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/kizanoxezus.pdfIn PDF document text
    • https://peoplehelppeople.net/uploads/File/wovofimasonudawulogux.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_off0000d542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD542 18564 bytes
SHA-256: 1a62b294c78abc8a44f7414611463a9ae066676f044a92d3b9d838655ce6c254
font_01_sfnt_off0001058c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1058C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011da3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DA3 10700 bytes
SHA-256: b38fbab6b228af80349a272411dbd38f95aac1e078bc24b2723a4bb921debc86