Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bfcfde77fd79166…

MALICIOUS

PDF

75.3 KB Created: 2021-09-19 22:01:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ef0c1c5743d2acd2c60bc09c2b064a24 SHA-1: 1764e5d763263311e6f590edbaa058a11b1c12be SHA-256: 1bfcfde77fd791666f0c800b68c36f4b96e07c0a9ad6281ac87a83b59ac5d6a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, with several pointing to compromised WordPress upload storage, indicating a malicious intent to host or distribute further malicious content. The ML classifier and ClamAV detection strongly suggest this PDF is malicious, likely serving as a lure to phishing sites or malware downloaders. No scripts were extracted, but the link farm nature is evident from heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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=8+ways+of+learning+aboriginal PDF link annotation
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/22562551305.pdfIn PDF document text
    • https://longhoang.vn/upload/files/83768958731.pdfIn PDF document text
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/gupajisuvifinugot.pdfIn PDF document text
    • http://yjeverspeed.com/userfiles/file/52789153558.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/111441457290.pdfIn PDF document text
    • http://straub-online.ch/userfiles/files/33154128513.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/54609579599.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/64814115497.pdfIn PDF document text
    • https://legend-chang.com/UserFiles/files/89338063601.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/gulaludezoxovatefol.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/geripito.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/35727375921.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/vejiferujiritopirek.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/lizawuzefonebov.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/48553387815.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/fd78181d79664cf55d22e5ec2311647d/92768998776.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/qtakoklbkaqqv44rujkpg3snp5/semulesulokivezeg.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f095921331---zizebejutezajemon.pdfIn PDF document text
    • http://stringladies.cz/userfiles/guxugeliwetakufudewilifu.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/88733848366.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/11397784669.pdfIn PDF document text
    • https://trieurodata.ro/images/file/18505511102.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/92378435315.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/kiwetabepapawuxatugemigo.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_off0000c374.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC374 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB86 16608 bytes
SHA-256: dc1930e9cbbe619483d3ce9d9301c30cb432dbec342896d314c2f6b3bf986885
font_02_sfnt_off0001064d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1064D 10744 bytes
SHA-256: 5c71e86598474e753b946ae3a8e8d768e90d9db737fce27d0b716c97a75e472d