Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b55e0059abc5b35…

MALICIOUS

PDF

78.9 KB Created: 2021-08-26 03:25:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 67a1a8d3a85782fbfc40caabd16d6d85 SHA-1: dd56c5343bff4dc34ab45e9df6f1598ade68abda SHA-256: 5b55e0059abc5b350c2cbe271e7eb12ba59e1a2c8b520753e579563bef207f34
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS upload directories and disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. No scripts were extracted, but the structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://thetestmag.com/userfiles/files/riberageb.pdf In PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/25et02rat1262ugqnia0agftgh/39598217710.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/kilanabamisaxuxudumowajos.pdfIn PDF document text
    • https://dolupin.com/calisma2/files/uploads/44887192204.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16093f358ed223---fimujawag.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f67830084a---sorojowixudegufugupu.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/33735893692.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d226b0555e9---gunikusa.pdfIn PDF document text
    • http://change4best.ru/upload/file/28731890988.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/xixajotaj.pdfIn PDF document text
    • http://kaiyudachem.com/filespath/files/20210821105313.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8fe564cc1a---misufajomitenojixunaxo.pdfIn PDF document text
    • https://ural-aiti.ru/admin/ckfinder/userfiles/files/12280581183.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a458aa07201---zawiva.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/39b741920c06bd8cfea2b7f26e1d92b6/92408214656.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/muwevisiwetajomipuze.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/17885586448.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/ralasutemadogixajuwidos.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608174ef1b08c---94217544928.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b221aa73483---62538076026.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/timomuxa.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/31946991395.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/3772267351.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160940beb4d320---17934937936.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/watisirimugefazim.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a67e722620---18098330010.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=space+exploration+for+dummies+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_off0000d1fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1FE 11056 bytes
SHA-256: b674bdfae39e1b1ea0945e3689193ff37771759f37041e4a2420e7334e2d9caf
font_01_sfnt_off0000ebb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB8 16416 bytes
SHA-256: 690cd88631713be0d9397183bef7092461e57685374aae01d1b9ced67d4868ee
font_02_sfnt_off00011617.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11617 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1