Malicious PDF — malware analysis report

Static analysis result for SHA-256 80db4cad3bd1b91c…

MALICIOUS

PDF

71.4 KB Created: 2021-09-24 13:10:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b2a561f6fb243876844779831347333a SHA-1: 83c5df972a920043e9b944cced5d10f37ae99fa4 SHA-256: 80db4cad3bd1b91ca830b8ba317aaef3960264a86e774787d7e0009f39feb040
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 pointing to external PDF files, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a pattern of using disposable hosting for these links. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection signatures suggest it may leverage PDF vulnerabilities or JavaScript to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://jinyudachem.com/upload/files/betizinaziw.pdf In PDF document text
    • http://theartofdesign.nl/ckfinder/userfiles/files/pejisutu.pdfIn PDF document text
    • https://bloc-immo.com/images/sobuxoruduratimareko.pdfIn PDF document text
    • https://esvigo.com/upload/files/lejegowaxiniwetoneban.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/wusabezabeloxipoli.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/kituxirawaxoniveruk.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/jasov.pdfIn PDF document text
    • https://laetitiabernard.fr/images/file/15457432592.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/kuxal.pdfIn PDF document text
    • https://o2opr.co/userfiles/files/80891575880.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/31107506461.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/96372007012.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210909195148.pdfIn PDF document text
    • http://jeanchapleau.com/userfiles/file/noragitoranevepexad.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/78074850521.pdfIn PDF document text
    • http://grupophi.es/uploads/files/43282648470.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/36456487382.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/zasirejibufugakafef.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd5413e26d---1923778731.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/10666753078.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/lejirepetemew.pdfIn PDF document text
    • http://konemara.hu/userfiles/file/jamavedutefim.pdfIn PDF document text
    • https://vr-spagna-20.effievirtual.com/galeria/files/33455519041.pdfIn PDF document text
    • https://mimpidia2.com/contents/files/50535608711.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=download+the+reels+videoPDF 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_off0000b179.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB179 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC98B 18184 bytes
SHA-256: 147cd15dabd66d853af5446a67bdda75642336fe97c43b3e00d9ff46178d398f
font_02_sfnt_off0000f87a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF87A 10500 bytes
SHA-256: e1165c76714f430513e68a551925132ab5e54668ed828459531a3bd66c80869d