Malicious PDF — malware analysis report

Static analysis result for SHA-256 b981052c893a32f0…

MALICIOUS

PDF

84.6 KB Created: 2021-09-10 04:04:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 23b8be7b9760fba93a57dc93ef480274 SHA-1: 6b6a155ecd05224b670ac0b0a7cd290fb2b8eeaa SHA-256: b981052c893a32f09a5ce5bdef1fd9070864ae5b833db6cf91da2b8d7b763f07
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to suspicious PDF files on disposable domains, indicating a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is designed to direct users to external content. No scripts were extracted, but the overall structure and URL distribution strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://daindnc.com/fckeditor/userfiles/file/masodemogum.pdf In PDF document text
    • https://ccskin.com/geektic/files/purixobagenawobib.pdfIn PDF document text
    • http://sapaelitehotel.com/webroot/img/files/lazusunudikevo.pdfIn PDF document text
    • http://irinabailey.com/upload/files/zatoxil.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/78144607789.pdfIn PDF document text
    • http://sbnjl.com/userfiles/files/99395020096.pdfIn PDF document text
    • https://tonmathunglan.vn/upload/files/jozujewuxedifozabanazi.pdfIn PDF document text
    • http://chukguwang.com/files/fckeditor/file/33650302981.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/18006729150.pdfIn PDF document text
    • https://woft-dining.com/webroot/editor-uploads/files/bibipimuruniwadarejud.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/83768151845.pdfIn PDF document text
    • http://bud-med.eu/userfiles/file/wavefojotokuledesatitezuw.pdfIn PDF document text
    • http://turchifiltri.com/userfiles/files/zafexaduli.pdfIn PDF document text
    • https://stopserv.ru/files/file/jijoxuduxafuxejoxapomi.pdfIn PDF document text
    • http://anshan56.cn/userfiles/file/16307814261034693775.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/23225331132.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/lajobozubezitozu.pdfIn PDF document text
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/61397445597.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/fewevidanogesisewonilizir.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210907073724.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/71393270387.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/59098029993.pdfIn PDF document text
    • http://kco.su/userfiles/file/25579757646.pdfIn PDF document text
    • http://pixel-pro.ru/upload/file/51954598189.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-9/20210909232038808074.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/zonowazulekabawaduwe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=periodic+table+of+elements+metals+nonmetals+and+metalloidsPDF 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_off0000e679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE679 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE8B 17264 bytes
SHA-256: ff826cfd79d5bace4eb90f8c4e1cdc1845d577a8da54b148822b0eeab936fbf8
font_02_sfnt_off00012b53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B53 10776 bytes
SHA-256: 5b87f7081d8f64385ce1d79e4338fe72be0c0dfaa80f525283cc48fc729298c6