Malicious PDF — malware analysis report

Static analysis result for SHA-256 50ff40eafec35ce7…

MALICIOUS

PDF

76.8 KB Created: 2021-09-15 13:55:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b003ab6dcf6543aae437f5f965ce1a49 SHA-1: 792f8855eac5c315131f720c8a1ca2a6d953a256 SHA-256: 50ff40eafec35ce7d9b7b07411e36ca33756a56130828073942229acbc946bd7
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting an attempt to obscure the true destination or leverage SEO for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/jiforudurenovatawipap.pdf In PDF document text
    • http://www.lbtfilm.com/uploads/files/voxivabumimukupuvikolava.pdfIn PDF document text
    • http://preiss.at/upload_files/files/41127049918.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/22736536032.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/90517888961.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/nufumolad.pdfIn PDF document text
    • http://fabriziocar.it/userfiles/files/14804210001.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/pogibotivot.pdfIn PDF document text
    • https://www.vignolaweb.it/ckfinder/userfiles/files/vaxixigu.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/fbddfba349e2c74df83582bed5036d8a/98686146674.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614118e33c4bb---16975664813.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/9bc177231affb8407076d39b4d03c482/18403254919.pdfIn PDF document text
    • http://cichanski.com/Upload/file/batemi.pdfIn PDF document text
    • http://cartopack.be/Images/file/suferuneravebobaza.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/3f5736191248b8d1be1459a917b021aa/dobepozetavitivapoxav.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/kiwogemuzugudaz.pdfIn PDF document text
    • http://precisionsurgicalworks.com/alpha/ckfinder/userfiles/files/taridalubekero.pdfIn PDF document text
    • http://lrm.mcdonalds.ua/ckfinder/userfiles/files/60970687646.pdfIn PDF document text
    • http://hichipper.com/hichipper/uploadfile/file/2021090522545973499.pdfIn PDF document text
    • http://grupophi.es/uploads/files/vokolaxeperuvaleno.pdfIn PDF document text
    • https://ptogel2.com/contents/files/xifujor.pdfIn PDF document text
    • http://inbond-cn.com/userfiles/file/xufamiw.pdfIn PDF document text
    • https://ww150005.linebot.net/upfile/files/20210904223021.pdfIn PDF document text
    • http://anduong-nhatthanh.com/uploads/news_file/42476829773.pdfIn PDF document text
    • http://quantri.thaisonpalacehotel.com/upload/files/gipusenidiluriv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=prime+app+on+firestickPDF 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_off0000c878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC878 10688 bytes
SHA-256: bfb11239d5c4a77e3a43de5aacced43957b7b3603383a1ace2ab72fece3e7d2c
font_01_sfnt_off0000e0fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0FA 17024 bytes
SHA-256: 8b84da31e618f6b3f3d60c2e92c17ac18b0799e8e60ae806be237c760057055a
font_02_sfnt_off00010d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1