Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57855db811e2692…

MALICIOUS

PDF

70.5 KB Created: 2021-09-26 00:53:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c22310528bc94126781c83f66626b3b3 SHA-1: 88f0167b4117defefe382846e0b6c3d51622da10 SHA-256: a57855db811e2692356483ffebff0c1bd44ab95e317d8f9851e1c7d8fd718a6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous unknown PDF files hosted on compromised CMS uploads and disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to lure users into downloading and opening additional malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/e0crm243o3v3is8p0rbl4bd4k3/lovulomer.pdf In PDF document text
    • https://szallas-karpatalja.net/upload/72710135738.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/fexisinosugo.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210917004702.pdfIn PDF document text
    • http://kvrhousing.com/uploads/69252838098.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/juwibi.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/6s8uto50sji38n07dmf59ori59/71680047772.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/50123259636.pdfIn PDF document text
    • http://maroba-zirndorf.de/file/3669798336.pdfIn PDF document text
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/rupuxegub.pdfIn PDF document text
    • https://asztromiskolc.hu/ckfinder/userfiles/files/kekobomukup.pdfIn PDF document text
    • https://dejavuruse.com/userfiles/file/4369282285.pdfIn PDF document text
    • https://termofriz.rs/files/72709698884.pdfIn PDF document text
    • http://sage-chem.com/image/files/20210913_191423.pdfIn PDF document text
    • http://oldmotorsclub.com/files/file/bewifoneloxetomepa.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/kedulusomepexozatefofekav.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/dadonagabe.pdfIn PDF document text
    • https://etravelbox.com/scgtest/team-explore/uploads/files/49636697455.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/69832241000.pdfIn PDF document text
    • http://laconchigliacasevacanze.it/userfiles/files/bezagu.pdfIn PDF document text
    • http://healhumanity.foundation/userfiles/file/58429814717.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbe7705cab---malovisomi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=aivc+pro+apkPDF link annotation
    • 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_off0000b14b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB14B 17680 bytes
SHA-256: 6b4a1067d3a96c8a805d34fb979e51205afec51e52853aa31e08f0dad7f5e9f9
font_01_sfnt_off0000de4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f661.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF661 9956 bytes
SHA-256: 303628a91dfcf5bf8269cee4af004fbc6f7f986556e2c27f8e04844261a77f0e