Malicious PDF — malware analysis report

Static analysis result for SHA-256 35b54c643e5965d1…

MALICIOUS

PDF

77.0 KB Created: 2021-09-12 06:24:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8bf3ea1284474fb3ad4d0e3b7a804e30 SHA-1: 3d93eb8edf81d4ac4bd7b0cdf19caa6fe97cd4a6 SHA-256: 35b54c643e5965d1b14283f234010821941d6927e1e4d5b2b6b214bc4d3d6db4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple disposable hosting sites, with one URL specifically mentioning 'windows 7 file download for android', suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the presence of numerous external links and the heuristic firings point to a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://krisoc.ru/uplcv?utm_term=windows+7+file+download+for+android PDF link annotation
    • https://inprovit.com/ckfinder/userfiles/files/lagivawepeperezup.pdfIn PDF document text
    • https://cesiedizioni.com/userfiles/file/83384411346.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/rimusevimunuz.pdfIn PDF document text
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81664264403.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/tawonuxigifovajidigipebuw.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7a40be1cc---tujedaketenareminirusopil.pdfIn PDF document text
    • http://csc028.com/userfiles/file/20210908112450_evfofd.pdfIn PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/narijilediletuwobijibexa.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb4c1e13f4---mibetatapuvupuwomovu.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/81236383168.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/62816766783.pdfIn PDF document text
    • http://faw-asia.com/image/upload/files/44603305959.pdfIn PDF document text
    • https://hobbypet.cz/files/file/4335534831.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16133b11085b95---dewafozevozes.pdfIn PDF document text
    • https://hirurgija.me/files/5921737416.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/1554753726131f43d0129a.pdfIn PDF document text
    • http://kawana.tech/userfiles/file/wemejavapepo.pdfIn PDF document text
    • https://fuze-pay.com/ckfinder/userfiles/files/99403920243.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/42569601782.pdfIn PDF document text
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/nejolokitefujixamuge.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/mubuxosu.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/49023473269.pdfIn PDF document text
    • http://brain-sh.tw/upload/file/kulakifafirinivupipok.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_off0000cb2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB2B 10376 bytes
SHA-256: 7bbf06e856479576329a2b48b3c2c777882c065a8f8e4090da0db8302ca63c34
font_01_sfnt_off0000e2d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D2 16768 bytes
SHA-256: 8a93cba9620a0e08436e5fd798ddced326cbc5df698ed7786ece6bc12ed159b7
font_02_sfnt_off00010e44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1