Malicious PDF — malware analysis report

Static analysis result for SHA-256 43c5542a9145db63…

MALICIOUS

PDF

75.3 KB Created: 2021-09-19 08:12:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0e57f61af7677c58b0cdcc83f635e725 SHA-1: 72642b50342db3d32bee1260ee97ab26a7d80617 SHA-256: 43c5542a9145db632ebbf5a99f052244a3c7b8e0fb10bc497e34812fe501b418
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to distribute links across many domains. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggests it's used as a delivery mechanism for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.jindatunnel.com/up_files/file/13834742690.pdf In PDF document text
    • http://yourhandmadeitems.com/userfiles/file/kotojufadupeze.pdfIn PDF document text
    • http://weingut-suppan.at/files/23745976276.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/wuxarafoliganiraluzote.pdfIn PDF document text
    • http://www.childofafrica.org/media/userfiles/file/numademibiti.pdfIn PDF document text
    • https://gulceoyunlar.com/calisma2/files/uploads/gobexerezilawilisokogarap.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/65117287633.pdfIn PDF document text
    • https://shivajigrihnirman.com/singhania/downloads/file/soxuf.pdfIn PDF document text
    • http://spbi.cz/res/file/55557023950.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/61069783696.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210905034958.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/91009535044.pdfIn PDF document text
    • https://cafepiolho.com/uploads/assets/paraxikepevulox.pdfIn PDF document text
    • http://hunicorn.hu/userfiles/file/sukudigutumavosisat.pdfIn PDF document text
    • http://geoscan.it/userfiles/files/47948694133.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/jederesib.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/86754286385.pdfIn PDF document text
    • http://lateonsettay-sachs.org/userfiles/file/kobizivazufudewok.pdfIn PDF document text
    • http://cattaneoarchitetti.it/userfiles/files/zuwiz.pdfIn PDF document text
    • http://kuhomania.ru/ckfinder/userfiles/files/36302669230.pdfIn PDF document text
    • https://sportsht.com/userfiles/file/rafadi.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/16574220985.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/e3a1dbcfae6d5230d9f4946dc6455e60/ratudujajepixekotadovef.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/1943055840.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/6529025340.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=critical+thinking+skills+in+mathematics+pdfPDF 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_off0000c3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3FA 16336 bytes
SHA-256: d334e1b6029818d7b514756e64db108d67ffc5775ddb35bed578ec489353ab53
font_01_sfnt_off0000edd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105EA 11068 bytes
SHA-256: 0c1b426154ff07da89a099537eda0dc25d995757c187d10e8304cc037e2fa572