Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d33f15c47e2bce…

MALICIOUS

PDF

84.6 KB Created: 2021-09-16 06:35:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: da868f889651e6a87d4881b6579b3e76 SHA-1: d0308c023b126a03b2aa2054aa40095c17a4ba02 SHA-256: 88d33f15c47e2bce9bf8cde7a7cb96f30b94b3cc06683c988bb716fa40223bc1
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 disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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=hungry+shark+hack+download PDF link annotation
    • http://slkuang.com/v15/Upload/file/2021951931353607.pdfIn PDF document text
    • http://georgewongdesign.com/gwd/upload/files/simidelena.pdfIn PDF document text
    • http://itaxabc.com/userfiles/file/20210901232120_859867231.pdfIn PDF document text
    • https://adminico.nl/userfiles/file/20319933859.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/basefirapekiziviw.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/17689172691.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109160727239511.pdfIn PDF document text
    • http://gerocuki.hu/user/file/xaxutuv.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/53987302303.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/29724120989.pdfIn PDF document text
    • http://tungalag.mn/userfiles/files/robujobavexuxal.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/58805857904.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/3240140616.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/wagibolovujajokifetexo.pdfIn PDF document text
    • http://immobilier-valence-agen.com/userfiles/file/tevegusumivofodola.pdfIn PDF document text
    • https://australiancaravancentre.com.au/application/third_party/ckfinder/userfiles/files/63224176384.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/wopasewokibax.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a151ccb476---8696354901.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/364ce5e2da85480d14bfb87dbb5898a3/29945687104.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109080914513174.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/d042b7b2a9d9e658ed380c1a3564287b/21233683632.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/rozebedize.pdfIn PDF document text
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/75808936049.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131172a645c6---6280551456.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/kofezularinavonunevubugo.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f59b8a4698---sitov.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_off0000e5dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5DD 10708 bytes
SHA-256: 4cdd88391835c65452d6a59aa23269ccb71bc887c1c1471af4bb146cfe5ea04e
font_01_sfnt_off0000fe32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE32 17872 bytes
SHA-256: 373cd41216d6ef00ba7ea3965857e788f36d4a1f5c9ad8ce4729ad0aef1b6409
font_02_sfnt_off00012c5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1