Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b3328779d28a9cc…

MALICIOUS

PDF

69.7 KB Created: 2021-09-26 18:01:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6538978d31595540b5b9a92c5b278b41 SHA-1: 56b17396b2927646b5fcc7973b099780bcb22bee SHA-256: 2b3328779d28a9cce246000bf6c86a8a6a025882326fb1d1c523d3128573d222
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous embedded URLs, many pointing to disposable hosting and employing UTM parameters, strongly suggests a phishing or link-farming attack pattern. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with attempts to redirect users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://ketchas.ru/uplcv?utm_term=how+to+enable+usb+otg+on+android PDF link annotation
    • https://computerzone.pk/file/zeturakuga.pdfIn PDF document text
    • https://pisangmanis.com/contents/files/84040434540.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/67837674027.pdfIn PDF document text
    • http://hakasasi.id/userfiles/file/6283882033.pdfIn PDF document text
    • http://abwingsde.com/uploads/files/53314477154.pdfIn PDF document text
    • http://studiogeologicotrilobite.com/userfiles/files/62711534655.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/151547562549.pdfIn PDF document text
    • https://gencshow.com/upload/ckfinder/files/fapusomev.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/2904548456.pdfIn PDF document text
    • https://webvitamin.vn/app/webroot/uploads/files/26070263463.pdfIn PDF document text
    • https://fontan-montag.ru/img/upload/86207919083.pdfIn PDF document text
    • http://zeguvietnam.com/uploads/ckfinder/files/46163841454.pdfIn PDF document text
    • http://prasongp.com/file_media/file_image/file/64604845143.pdfIn PDF document text
    • https://jotelek.hu/files/file/1688276794.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/fokajodiralokopawezeli.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/rusegigopepime.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/91326443303.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/tobafepa.pdfIn PDF document text
    • http://kids-ex.com/images/blog/file/26039832747.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/50087033922.pdfIn PDF document text
    • http://st-communications.com/ckfinder/userfiles/files/fugemumojezukegul.pdfIn PDF document text
    • https://ice-group.pl/userfiles/file/wisewofirawovudino.pdfIn PDF document text
    • http://ersenergy.com/UserFiles/file/jaduga.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/75341937239.pdfIn PDF document text
    • http://slmj8.com/data/userfiles/files/wikuvavukutofo.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_off0000b2dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000caf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF4 10740 bytes
SHA-256: 28f0878a1d9a6e775c71b11fb775ef61ffad2e418403395782857d1e098bda68
font_02_sfnt_off0000e38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38D 14872 bytes
SHA-256: 7bd64d23e602e9e05c880409a97f9b71f23773ced84806e36702e59fc5811310