Malicious PDF — malware analysis report

Static analysis result for SHA-256 877bd3dff0804e7a…

MALICIOUS

PDF

80.6 KB Created: 2021-09-21 05:30:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 04653410a073b1739abe2d42aa938ce4 SHA-1: d8050891ea033120bc74b77192580154b429fe1d SHA-256: 877bd3dff0804e7aee2719f80b6524512fc5a26f81bdb967b2816e31ce636646
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://chcial.ru/uplcv?utm_term=best+android+english+dictionary PDF link annotation
    • http://iphonedown.com/ckfinder/userfiles/files/77358898094.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/27921611355.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210906_082509.pdfIn PDF document text
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/30092427525.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/23716294907.pdfIn PDF document text
    • https://mkontakt.com/dat/file/pelumezituwuwirewefo.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///mademufagivujuvesizefa.pdfIn PDF document text
    • http://peetersinstallatietechniek.nl/upload/files/32333772609.pdfIn PDF document text
    • http://szjglaw.com/uploadfile/file/2021091804170873499.pdfIn PDF document text
    • http://maymaygiaydachidang.com/upload/files/dinozukimanazopigup.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/fizuwepapadepow.pdfIn PDF document text
    • https://sgicorp.com/userfiles/files/pozuxakalerejozepogobe.pdfIn PDF document text
    • http://music-saikung.com/ckfinder/userfiles/files/174821042.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/16527001723.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361c42514db---40346385820.pdfIn PDF document text
    • https://redac.ch/upload/lebelovabo.pdfIn PDF document text
    • https://www.fishhabitatnetwork.com.au/application/third_party/ckfinder/userfiles/files/61761940020.pdfIn PDF document text
    • https://lederstuehle-shop.de/ckfinder/userfiles/files/75247354112.pdfIn PDF document text
    • https://jmbarrenetxea.soinuenea.eus/files/galeria/files/wogopiwofizijafakexejizik.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/b2473d370985cc170265df7598cf4d50/80160770734.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/70896249284.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132493476f34---25653417146.pdfIn PDF document text
    • http://perfekt-dom.pl/designhome/admin/userfiles/file/81939594756.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/4255549166.pdfIn PDF document text
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/91736575488.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_off0000d77e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD77E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF90 17292 bytes
SHA-256: 229c7d6fd7be35608781b74bbdd82b9720554b8ef9b7e2df1873882c0111495c
font_02_sfnt_off00011c68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C68 10816 bytes
SHA-256: 0e552da20ab5da37874c0975b2ceb45edceb7c1e14ffd7a316c434081b074cde