Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bc8dfde584b6003…

MALICIOUS

PDF

68.9 KB Created: 2021-09-28 01:30:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6e59070b5fb08364b7e8b2bc9e00cbf9 SHA-1: 47a29fba42927de2ff3382e0ccfcf5fc87ce5360 SHA-256: 4bc8dfde584b6003a1752f9041c539cc2b6feea9e1226563325bd8da807731e8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to potentially malicious domains, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the document is part of a link farm designed to obscure the true destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://losmarinoslanzarote.com/marinarubicon/admin/file/21986296396.pdf In PDF document text
    • http://pobierzplik.pl/uploads/files/fejeku.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/66463424791.pdfIn PDF document text
    • http://grupophi.es/uploads/files/terufewotutusabutekun.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/40444241734.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/kivujolix.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/67938948381.pdfIn PDF document text
    • http://purevdavaa.mn/uploads/ckfinder/files/87047756520.pdfIn PDF document text
    • https://steammining.com/userfiles/file/digeguzimabojaratipup.pdfIn PDF document text
    • https://horizontire.com/userfiles/file/43389657671.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/detajotofelejidefugotak.pdfIn PDF document text
    • http://velomagazin.hu/UserFiles/file/8362811284.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///20933999155.pdfIn PDF document text
    • https://fivetc.vn/uploads/files/47568211974.pdfIn PDF document text
    • https://healthmatters.me/userfiles/file/53857632322.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/52682057500.pdfIn PDF document text
    • http://ohxto.com/uploaded_files/userfiles/files/62683425980.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/9918814066.pdfIn PDF document text
    • http://21cedu.com/pds/userfiles/files/dolutopesezape.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/ruvabiwukefagobevim.pdfIn PDF document text
    • http://gmart-express.com/demo/uploadpic/file/6439412165.pdfIn PDF document text
    • http://k-souz.com/userfiles/file/vagalewojedavepurimarafos.pdfIn PDF document text
    • https://activsport.ro/userfiles/file/lupuzebanezew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=android+phone+password+unlocker+softwarePDF 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_off0000adc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADC7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5DE 10976 bytes
SHA-256: 40f7be8dd45cb3800dbfc15c8c61aef9511755a174fbbcb6a66cd62c500fbe7f
font_02_sfnt_off0000df58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF58 15048 bytes
SHA-256: ba89e54775c4ac585511a003a76032c5e0138a0c8c7aa19b3a4fb747b0fb4c67