Malicious PDF — malware analysis report

Static analysis result for SHA-256 35bfca0af3533197…

MALICIOUS

PDF

93.7 KB Created: 2021-07-05 14:33:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91cac83d34cb3b97767511ae2ebb5726 SHA-1: 2a99e53e51861de807c7acb6937abf0e12dcc446 SHA-256: 35bfca0af353319733d54d07998eaf75d9c5edac4e50c725e46aa871f370cc43
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving the exploitation of PDF vulnerabilities to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://windsbs.biz/files/file/xuwogalobaz.pdf
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/92b5f5525b67c0337502648353afb7ad/5349104378.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608a3e2b1dbf2---tadazuposimujatebu.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/e2ef623a572cb7a96b037a3627832d5c/43866139223.pdf
    • https://linker.tw/files/danodujerugini.pdf
    • http://wonikqnc.com/upload/editor/file/1623431762.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1609a956ab1434---woweliberedofitito.pdf
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cb6e615e0---gofafokigalupumisuka.pdf
    • http://flirdining.com/uploads/files/nuleriraxir.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/lochbcigt2v8vddrs1jm4kir85/18326813279.pdf
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cedec1af351---61836501749.pdf
    • http://extintoresorigen.com/images/editor/63200643374.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef4c6decdd---ropogonip.pdf
    • http://matstravel.ru/userfiles/file/zaporowe.pdf
    • http://cuboni.com/uploadfile/hong202106231903044088.pdf
    • http://suachuabaoduongmaynenkhi.com/img_quanganh/files/kowaxevopulemiwosamedi.pdf
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/ad3639cd64e04fc96a5af9c5dd0abfb1/jinawixosotegapijar.pdf
    • http://xoblates.com/clients/e/e0/e08cfb93fb97b00c28394d0532709dc9/File/72770691631.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c241b5f70b---23477003378.pdf
    • http://shuswapladystriders.ca/userfiles/file/fodobobixolule.pdf
    • http://yomamasushitogo.com/uploads/files/77417791992.pdf
    • http://dzbnf.com/upload/file///70956217173.pdf
    • http://status-go.net/gfx/userfiles/files/wegesaz.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16091a5c0ecb92---33024953046.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=hoarse+throat+causes
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010e3e.bin
93e49c4cc8030520668e1bf29271dde6867b876ae4db217e0f3247247f5d8cef
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3E 17036 bytes
font_01_sfnt_off00013aa0.bin
552e5aabe6e952ebc8c784774e267a97cd08bf79d1f8cd7dd0a2d5f04983fe66
pdf-font-stream PDF embedded font (sfnt) at offset 0x13AA0 10176 bytes
font_02_sfnt_off00015192.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15192 16792 bytes