Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1cf4934c3c08e05…

MALICIOUS

PDF

80.8 KB Created: 2021-09-18 18:53:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 48bc21fbdbc84f0f2071abe925b5e621 SHA-1: a3d7f0ef4f8502633d238466ffeb0b3be8020ecb SHA-256: b1cf4934c3c08e051c2d02bbf08776646a0254b4c226538d5ad20e1f3a199400
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm with numerous URLs hosted on various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. The presence of embedded URLs and the nature of the link farm suggest the document's primary purpose is to redirect users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://synerhu.ru/uplcv?utm_term=gta+sa+visa+2+apk+download PDF link annotation
    • http://netichikawaya.com/userfiles/file/20967330931.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/egk0e9q3eukep0qmnctbet7acq/nonininanirutefotutore.pdfIn PDF document text
    • http://cudicio.it/images/file/12207105337.pdfIn PDF document text
    • https://drjou-vc.com/upload/files/32295876164.pdfIn PDF document text
    • http://xn--2e0b95unoa536adofm5h.com/userfiles/file/zavapevexalajulusorodovaz.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4a245c966---49642163788.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/14541533634.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/mugewagizonaf.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/kii0eo31ar7f0n2fbp6a4bglfh/16004461058.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/7707406755.pdfIn PDF document text
    • http://vsrru.ru/userfiles/file/jegevezet.pdfIn PDF document text
    • https://art-eria.pl/mandarynka/pliki/files/nogajuvenodusinokaz.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/42389400789.pdfIn PDF document text
    • http://daydreamspin.com/userfiles/file/79806267009.pdfIn PDF document text
    • http://consade.com/userfiles/file/40295778961.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/parizelaragugutadebijawu.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/ponogemakuduz.pdfIn PDF document text
    • https://purevdavaa.mn/uploads/ckfinder/files/jomire.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/0a5ee2a99432dddd70d750dd96278c03/39314508402.pdfIn PDF document text
    • http://hzxgdz.com/images/upload/File/livividokitu.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/wosovozepa.pdfIn PDF document text
    • https://libertyrealestate.in/ckfinder/userfiles/files/xumuxoxin.pdfIn PDF document text
    • 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_off0000d41c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC33 10556 bytes
SHA-256: 12d065b0cc219a79ee25e470391b504a45e69e966381ac584623f0d5ab1ee631
font_02_sfnt_off00010488.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10488 18660 bytes
SHA-256: 9316e26e25b716d4e252bec64ef182acc7d2138bd4eda43de4663a85fa995f96