Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31b272c558ce1db…

MALICIOUS

PDF

77.7 KB Created: 2021-09-06 13:50:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 340335d77a412b06ef2a5ec0e70d9b30 SHA-1: 9d1ad3a700e3cd819f3e81825ecd0115fcb4e8ea SHA-256: b31b272c558ce1db42e0004b82d29b3ccac60d9f58eafa814bdb5b243bb4ff71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to compromised WordPress sites and disposable hosting domains, suggesting an attempt to lure users to malicious content. The presence of these links, combined with the overall structure, points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c06e19344aa---gebeg.pdf In PDF document text
    • http://auto-spec.ca/fck/file/sidoberodala.pdfIn PDF document text
    • https://mavachhaiphong.com/upload/files/19156541074.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160943b0a4b07f---9620410531.pdfIn PDF document text
    • http://officeharbor.com/pdtInfo/50675224365.pdfIn PDF document text
    • http://alkanboya.com/files/file///855359659.pdfIn PDF document text
    • http://cooper1972.com/clients/b/b4/b451ebb09e7e0345645526f893d9a49e/File/89381481231.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e407dd0410---kixofoxovaxela.pdfIn PDF document text
    • http://circuitvietnamcambodge.com/hinhanh/file/17713262841.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fc15646ff54a71bb645486a72fb305fe/76678240811.pdfIn PDF document text
    • http://nceed.kr/pds/userfiles/files/matelofugozedes.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/7815091797.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xokifo.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1505b48decb7a04a55a83824355d3d7b/fijix.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/682dc2ae9658f41a5c8d9e9363268b08/17221633274.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/lqind92k38v22h2jt8tf3v9r91/duwonusur.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/90285bf68d49e8fca141461052cbad64/64035814408.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e297ed41c92---dazukebesuk.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a78761eb69a---30688972557.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/0587c89d377ff32ad6429664605c276f/dirusovomopipumefi.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/52729170690.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210519012530.pdfIn PDF document text
    • http://bmhs1963.com/clients/7/72/7286fd37811b7a5dece6e69924e4d5ab/File/vuxomatujen.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160859d5ac5aad---12375586077.pdfIn PDF document text
    • http://forspeed.cz/ckfinder/userfiles/files/kenevozosijon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=competencies+list+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_off0000d023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD023 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e83a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE83A 10548 bytes
SHA-256: 7df4a0b6fd717ec4867f2ed148a18be7a0ff5efe3724ac4c75e7102a7a5676f4
font_02_sfnt_off00010035.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10035 16244 bytes
SHA-256: 267aef4cba4c866ade4727c475988388d8ee087f8bfc32ceebf58eac72212bde