Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a881448d0bbb321…

MALICIOUS

PDF

95.4 KB Created: 2021-07-09 16:43:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 58fc6ef843c0bf2a4ec448033f8ade5d SHA-1: d9655105fbcd2c4e0b427265988aa75c5f614255 SHA-256: 4a881448d0bbb321d52bb749fb658790f929ff09a51fbb3e0882a3f605fbd218
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a malicious PDF that uses a fake invoice lure to entice users to click on links. It contains multiple links to compromised CMS upload storage, suggesting an attempt to download a second-stage payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://londonvipchauffeur.co.uk/wp-content/plugins/super-forms/uploads/php/files/aad167cb2d172d4a10cccc458f5a4d3a/34645555037.pdf In PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba83825322f---10032971175.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/11963c0f73dd2b75f44881de589e29c7/velijogedomolalututo.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7ffbde8e5---16145453526.pdfIn PDF document text
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/7c9e2fec48908a391284913ee3bb5bd4/3216394765.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/85a9c4d63dca7e30b065cf9889efa194/batexakudokaposaruvaz.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/o071bmvkus3npeai01er6nr7ku/18165836679.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/23750147239.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/eaa65034996e17c9d9c58f4a214577d9/pajavaneg.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5eee504358---26405965755.pdfIn PDF document text
    • http://douzonebnf.com/upload/file///17873415569.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1609cdff492f26---musizozafavirufodesal.pdfIn PDF document text
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/22666168162.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160763f5ed0c03---leketifevedafedofokofef.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/1cc0998f48d0d808b80e273d040396cc/tijobezuwixaloxakosefuwuz.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/121dedaf248ecd178af4f533a76b4612/duguzoneduvedugamuweje.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/sesekowasaburunobopo.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/002e069546535e366f2608a5e910e7c8/70798899604.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/wegirinat.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/407044584.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=guilty+conscience+quotesPDF 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_off00011212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11212 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012a29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A29 10360 bytes
SHA-256: 57d5588bd017929c59c1f4e353131c92014a94933684a2ffb1ed6a12920efa32
font_02_sfnt_off000141c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141C1 18364 bytes
SHA-256: 83cc975e4d06d7b76d2433168754943154a3240955607d9fcfa695a5154f5058