Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac93efa066af2cfb…

MALICIOUS

PDF

85.8 KB Created: 2021-09-19 00:33:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dd8e0de93ac2db57391efe9dfd31c8b4 SHA-1: 777532faa0f55701e1f22db7c20f5ef3788ae0c8 SHA-256: ac93efa066af2cfb3718609d3c14640b18fda5a802c3b618a0b4038856509988
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs and is identified as a link farm, with several pointing to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the nature of the link farm suggests it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://medvor.ru/uplcv?utm_term=k+in+k+means+clustering PDF link annotation
    • https://pianotuningdarwin.com/userfiles/files/samipopakixinoloxuz.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/vavajefigiji.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/toxolatokasinosezoriton.pdfIn PDF document text
    • http://derp74.fooden.com/UserFiles/files/nonabo.pdfIn PDF document text
    • http://trovas.com/userimages/zedavunagomoxunim.pdfIn PDF document text
    • http://finara-v.com/file_media/file_image/file/54219107008.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/femuzevejuvidix.pdfIn PDF document text
    • http://blfimmobiliare.com/userfiles/files/dunokapipajiluvamixuxulaz.pdfIn PDF document text
    • http://vilocom.net/webroot/img/files/32410547696.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/734b3565cd156b4b132e9126e79e06af/33903432868.pdfIn PDF document text
    • https://euinsuti.uniluxgym.ro/app/webroot/files/userfiles/files/54665034715.pdfIn PDF document text
    • https://netlandschool.cl/files/xazim.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/lopiradalirunogudak.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613573ed35be8---fupagex.pdfIn PDF document text
    • http://takramaipai.com/mypicture/file/26387017211.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/62083218454.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/iqjnsg5ue510psv9bq0pnk6ats/kisumuxerojaf.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/suwewabipodunefezusevigup.pdfIn PDF document text
    • http://location-appartement-venise.com/italie_documents/files/dixivagunafub.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/shaipu321atf5eq5em8a940qua/8055652268.pdfIn PDF document text
    • https://perfecthospital.net/ckfinder/userfiles/files/nufubasekekekuderaligoza.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_off0000ea45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA45 18012 bytes
SHA-256: d78144e2f347448a811ce0c84191f3108522f4942659387f008a304afe7b12b7
font_01_sfnt_off0001195e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195E 10636 bytes
SHA-256: 55d9502c804a06b0e7c5ef9d851c67957f5dc795005bce51f29b509ccca35b25
font_02_sfnt_off000131a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1