Malicious PDF — malware analysis report

Static analysis result for SHA-256 a88a6159d9ff9055…

MALICIOUS

PDF

70.8 KB Created: 2021-09-26 09:31:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 169654663fa9e027af30acc239a472e4 SHA-1: 5a0f2bb1b07c6b0b241b6ed4311a24d8e594d7b2 SHA-256: a88a6159d9ff9055400200e05a321154f1792d7aaa91a32da456686b3f2214b5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, and ClamAV detection confirms its malicious nature. The ML classifier also flagged it with high confidence, suggesting a phishing or trojan distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613835134d5cb---33167051067.pdf In PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/079lhvbn80m4ue6f6e6dribqem/zaxisiw.pdfIn PDF document text
    • http://jgbt.us/pds/userfiles/files/todekemolozusan.pdfIn PDF document text
    • http://nusratali.com/userfiles/files/79369593600.pdfIn PDF document text
    • http://cee1968.com/ckfinder/userfiles/files/filitirupevobabore.pdfIn PDF document text
    • https://pisangmanis.com/contents/files/58519317720.pdfIn PDF document text
    • https://5ky13lu3-1251.com/contents/files/44640249760.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/wotabojuva.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/37349581690.pdfIn PDF document text
    • https://swapnauraan.com/ckfinder/userfiles/files/46900589884.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/31565573022.pdfIn PDF document text
    • http://iscelenie.info/files/file/tubibopokorupizasisadujog.pdfIn PDF document text
    • http://www.siposferenc.hu/html/begelo.pdfIn PDF document text
    • https://digicpictures.com/downloads/92377768866.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/29635483615.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/zetelugomin.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/89121981665.pdfIn PDF document text
    • http://ecoaga.com/documentos/file/85965631470.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/woroxelavuzipapikodi.pdfIn PDF document text
    • http://sheilahancock.net/blogfck/file/17017827691.pdfIn PDF document text
    • http://qfse.co/images/uploaded_files/ckfinder/files/1630611891_3cf0fdf61d.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/tijojole.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/49703027733.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a2e884c46b---99436386564.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=remove+all+certificates+androidPDF 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_off0000b2d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2D7 10748 bytes
SHA-256: b38aad049761dc0c1c150a438f58df967fab75201efcc4a0c2ac3d1887a404d8
font_01_sfnt_off0000cb92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB92 16412 bytes
SHA-256: 7f88aacddf74af7664aec3312978c507c9a7f76266bfd1221250d7eccebd7399
font_02_sfnt_off0000f56a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF56A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1