Malicious PDF — malware analysis report

Static analysis result for SHA-256 28cb8109318484f2…

MALICIOUS

PDF

84.6 KB Created: 2021-09-14 19:15:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5f18a5cbd9c175076d928f31f7934fe7 SHA-1: c717403a19b67f1ea3a91c2ce31cdff3450e8365 SHA-256: 28cb8109318484f2f6e17b32049d3dadef6e84d19044464c8a844624e9216540
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. Although no scripts were explicitly extracted, the nature of the URLs and the detection indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://dungcumaymoc.com/Images_upload/files/ketadogujatixiberavapebat.pdf In PDF document text
    • http://kbinteriery.cz/userfiles/file/turefu.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021971428377187.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c3d52c778---58909103858.pdfIn PDF document text
    • http://sherwoodonionfestival.com/ckfinder/userfiles/files/fopezoxigapanokugijim.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/lulazivolijimugegimagelo.pdfIn PDF document text
    • http://emke.hu/uploads/ckfinder/userfiles/files/wulowug.pdfIn PDF document text
    • http://uran-berlin.com/userfiles/file/24112190633.pdfIn PDF document text
    • http://homearcky.nl/userfiles/file/lawizawibusarogap.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/vabarefilipusewatifur.pdfIn PDF document text
    • http://xn--pr3b03lcdvwu9dpynqkc.com/DATA/file/20210911115751.pdfIn PDF document text
    • https://aviatroglo.fr/IMG/file/44849114704.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f14115d4b8---14383121732.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/93693479151.pdfIn PDF document text
    • http://knauto.com/upload/file///vefapiguju.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210909222851.pdfIn PDF document text
    • http://labotinnghia.com/img/files/fagapulobefopupowubozalu.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/pisufeluxikixowejagave.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/9036098973.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090122245572814.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/goxunedizezuxawopilusanen.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161373b2f6d406---rikonunabasagavev.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c2086c5dd---lesoxusitawuxaxefagisup.pdfIn PDF document text
    • https://umutfm.com/resimler/files/7370146179.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=tiger+zinda+hai+full+movie+2018+720pPDF 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_off0000d8ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FF 21532 bytes
SHA-256: f505dd25c676d6b35df43a9321ab0e86519ca7ce9d256d4e2c66aa961be7eef3
font_02_sfnt_off000129c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129C5 11420 bytes
SHA-256: e5e16ef02815bb0beecd8bcf028261ab4cceee8344c12a72a951890344fda008