Malicious PDF — malware analysis report

Static analysis result for SHA-256 5759c500c9b64778…

MALICIOUS

PDF

81.3 KB Created: 2021-09-14 12:37:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 85bf36941e354f18b1365fd3f3f72eb7 SHA-1: e4c6e6039a517169d9e7d1e1495f525dcab643e3 SHA-256: 5759c500c9b6477851ef1c9453f49605160095e7e88283f3931178e826d4f024
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing structural elements that likely facilitate the redirection.

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://gitteszoneklinik.dk/ckfinder/userfiles/files/tipewuxikefitumumomiwix.pdf
    • https://verner.lt/images/files/laxaxalimaxudifila.pdf
    • https://shop-ecobati.com/medias/upload/files/jexariwumoxipemufomo.pdf
    • http://mnwebdesign.dk/userfiles/file/rosedofajij.pdf
    • http://edu-family72.ru/content/images/uploads/file/xidopanodunijidepamu.pdf
    • https://aiwatopup.com/ckfinder/userfiles/files/jufarisig.pdf
    • https://clinicamanila.com/ckfinder/userfiles/files/68753103937.pdf
    • http://ambcavallon.eu/userfiles/files/gason.pdf
    • http://millionsdiscount.com/mo_images/files/30464864753.pdf
    • https://luathoanghuy.com/uploads/files/vonag.pdf
    • https://karapinarinsaat.net/userfiles/upload/file/dixadogevawokolomufegari.pdf
    • http://shceping.com/upFile/photos/2021-9/file/98715286434.pdf
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/mukeritotumanomof.pdf
    • http://hzbmsj.net/images/upload/File/43539268155.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16135b131536c5---viwusizuwusevuwumuluwado.pdf
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/52aea0520b46a6abb21e93c1fb3b9329/diwivitegebewokoteparok.pdf
    • https://georeno.ca/userfiles/files/20844013176.pdf
    • http://sahrugs.com/userfiles/file/65817520289.pdf
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161398bda7a92c---80645840208.pdf
    • http://jumpstart.mobi/userfiles/file/10344801208.pdf
    • https://infotechb2blite.com/bot/ckfinder/uf/files/255074085.pdf
    • http://puisan.ru/uploads/file/93224688639.pdf
    • http://alda.pl/ckfinder/userfiles/files/94100207673.pdf
    • http://puntolinea.org/userfiles/files/35231465927.pdf
    • http://gmkms.net/upfile_editor/2021/files/winuzeloruli.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=stomach+anatomical+regions
    • 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_off0000db6d.bin
1faf706b398fe03d979aa42a50391eee0916734eb2dab92316b26f5e2547b169
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6D 16980 bytes
font_01_sfnt_off00010741.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10741 16792 bytes
font_02_sfnt_off00011f58.bin
a27c16c9ef3e7dab2b62c690e6ee8154dc0c741574117d0ecf96272905cba249
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F58 10752 bytes