Malicious PDF — malware analysis report

Static analysis result for SHA-256 71710eb2ff6b7c3f…

MALICIOUS

PDF

94.3 KB Created: 2021-09-14 12:03:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 2450637e7e689fe6e19b4a29705c0759 SHA-1: a0479945d864318b14d4aa070371aadc4286af4d SHA-256: 71710eb2ff6b7c3fb0864207bd7b8a462784a14df23794283f21157fe5100999
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various PDF files hosted on different domains, indicative of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the presence of many unknown URLs strongly suggest this is not a legitimate document. ClamAV detection and ML classification further support its malicious nature, likely for SEO manipulation or as a distribution point for other malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://foodzipo.com/uploads/userfiles/files/duridogulivubinazaziw.pdf In PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/27945585319.pdfIn PDF document text
    • http://toflight.mobi/attachment/ckeditor/files/f6e922c914b90aa54d00c75fb214108e.pdfIn PDF document text
    • http://aeon-dev.com/uploads/files/202109030104173149.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/fozonuzubal.pdfIn PDF document text
    • https://shevian.com/images/file/rezogaxetizowojokediv.pdfIn PDF document text
    • https://lensprovn.com/ckfinder/userfiles/files/15857970017.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/bezatul.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210911181706.pdfIn PDF document text
    • https://pmfegypt.com/userfiles/files/vajodufedelinewagitudugi.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/xigepibobafowujasor.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210905223041.pdfIn PDF document text
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/wufewexewizobavekevizo.pdfIn PDF document text
    • https://ruedi-leuthold.com/userfiles/files/68980544218.pdfIn PDF document text
    • http://tnslib.su/userfiles/files/duzetotun.pdfIn PDF document text
    • http://qbcar.ru/ckfinder/userfiles/files/pebugubiwikufes.pdfIn PDF document text
    • http://triatlonbizuterie.cz/sites/default/files/file/xeginizog.pdfIn PDF document text
    • http://hyundainhapkhau.net/upload/files/rimatekotalividepezo.pdfIn PDF document text
    • http://rhondachem.com/d/files/norusafumodeberadenitigat.pdfIn PDF document text
    • https://loyd.rs/images/file/gubapuxerezobiduruvazu.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/xuzozafuduro.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/80909705718.pdfIn PDF document text
    • https://ferdavagnar.is/images/fck/file/sutekolebezotap.pdfIn PDF document text
    • https://www.domaine-vrignaud.com/ckfinder/userfiles/files/fosub.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/bunemapazepofanafupikanoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=return+to+oz+putlockerPDF 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_off00010d4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D4E 18064 bytes
SHA-256: 9152fb1b055051f2c6464725ce3b627d9d184604f841aadc12b64d43cc9425fe
font_01_sfnt_off00013ca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CA3 10244 bytes
SHA-256: dc1de0f210112dd319fa6e4cd9c8a0f1f670f93719afb7ad43f817f7509e534d
font_02_sfnt_off000153d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1