Malicious PDF — malware analysis report

Static analysis result for SHA-256 15a113a352b7a3ca…

MALICIOUS

PDF

84.0 KB Created: 2021-09-03 18:48:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8117164f05d11da822809bbdad594c07 SHA-1: 48285930e1ba47598f6e91160b6d152076b2d0c4 SHA-256: 15a113a352b7a3cabc2d5f86ab3a974fb314f98af2c0daa14644f602c4a7a634
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous links pointing to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=teacher+absenteeism+pdf PDF link annotation
    • https://qualitymattressfactory.com/admin/userfiles/file/jexosaku.pdfIn PDF document text
    • https://webtechnocrats.com/upload/file/54621540227.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/68442933118.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210518013844.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/ferofozugijotevufej.pdfIn PDF document text
    • http://teplospectr.ru/images/files/muvosidokal.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/1nl9668h2ndqv6i9glt8gkkd60/13243067225.pdfIn PDF document text
    • https://camelcarpet.org/d/files/93961809209.pdfIn PDF document text
    • https://htddienstverlening.nl/userfiles/file/8467732226.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/42929191886.pdfIn PDF document text
    • http://robbes.nl/media/files/nukifiwanufajazuwigijogeg.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/75dbv2gidij69qhkhqcvacr7m0/11516092336.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e58d0c6be6d---gurabepup.pdfIn PDF document text
    • http://vtaky.sk/media/file/lojefijibunixaxari.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/zamunu.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160bc07e007dd5---54885530094.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161031596ae052---ruxikokopigufetavudaruw.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/ximozetipikesor.pdfIn PDF document text
    • https://demircanticaret.com/userfiles/file/12887549195.pdfIn PDF document text
    • http://dastone.ru/userfiles/file/33795418385.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_off0000e3e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E1 10820 bytes
SHA-256: ebe098411977484ddcd0f9c54d2a05b528546697d6b7987b95671003fdbfb3c2
font_01_sfnt_off0000fc69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001147b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1147B 18112 bytes
SHA-256: 06cea918d96004350fc34834481db7e2367e63cc4cadb0c42046d56e2a98dc7a