Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ac8f3564cc33674…

MALICIOUS

PDF

86.9 KB Created: 2021-09-01 21:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a5ae66dcbc097db8111cc38bb6e3d340 SHA-1: 7867773e436157be1cbca1f256653b8a64083b2e SHA-256: 6ac8f3564cc33674a90b4aef0ccdd83d529c981abf3800dcee5b638d08f2d6c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to compromised or disposable domains, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of techniques used to deliver secondary payloads or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://infrive.ru/uplcv?utm_term=the+werewolf+of+fever+swamp PDF link annotation
    • https://ayurmitra.com/files/file/sovibijemakigozabibozup.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/39228010916.pdfIn PDF document text
    • https://monyetmesum.com/contents//files/wudisitavigogufupodefu.pdfIn PDF document text
    • http://arucax.am/user_images/file/83278912159.pdfIn PDF document text
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c990055bf7---fisidufepikugumubiwegapa.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/681e945cfc8d40d6c527bc4f82236134/81345213705.pdfIn PDF document text
    • http://stembridgefamilyreunion.com/clients/0/0d/0db03be1a97f3028174cafb645c8c91f/File/35861753210.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa//files/gujolud.pdfIn PDF document text
    • https://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/2d3c1089bdd249c89deca819c716a7a2/fuvulelidisosedov.pdfIn PDF document text
    • http://uni-farm.pl/ckfinder/userfiles/files/gomozez.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/434825682.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a07ffc6c237---nilepovefiwefewuxidi.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/tolifefixamizu.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/rinamewuduxunatuzi.pdfIn PDF document text
    • https://netkat.in/ckfinder/userfiles/files/40542145185.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/bawateva.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///lewanufaviri.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/14812573988.pdfIn PDF document text
    • http://austintownfitch1980.com/clients/879833/File/maxolekezekexores.pdfIn PDF document text
    • http://gddfboiler.com/uploads/files/67269696998.pdfIn PDF document text
    • http://viethanit.vn/hinhanh/file/veredod.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_off0000eff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF9 10444 bytes
SHA-256: d6fbfe4c8595b32400db30038e63a3ee465e77250842acd144f0beec137a938b
font_01_sfnt_off000107cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CB 17664 bytes
SHA-256: bf3c5e85940679a75640c39dabf23341c3bd6785797238eca280e7ba82d8db99
font_02_sfnt_off000135cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1