Malicious PDF — malware analysis report

Static analysis result for SHA-256 41b7e799f94c6732…

MALICIOUS

PDF

90.0 KB Created: 2021-08-31 03:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 83f280c7666b18de89110ddee92084ff SHA-1: 8c6b6bdf771d738af0c15660d08598faf45a7041 SHA-256: 41b7e799f94c6732276d97a7d711b08d895037f81eabd299dbaa5939ffc5454c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs that point to compromised WordPress installations, likely intended to host further malicious content or phishing pages. The presence of external URIs and compromised CMS upload links indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://chcial.ru/uplcv?utm_term=steph+and+dom+son PDF link annotation
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/e667b066089e4415713e5785a5e7b87b/56909333661.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/31bc20bfe8a92973d16044031c652d0e/92893445567.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1606c87ec1729e---53202539583.pdfIn PDF document text
    • https://egf.tw/test2/images/file/28593714618.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/sutobazakuwupujijome.pdfIn PDF document text
    • http://www.sec-ollivier-associes.fr/www/upload/file/24701705329.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/35614137327.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/001feda47f5629e6ef004af0e3e7c061/vukakexul.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca1331a364---selapomowul.pdfIn PDF document text
    • https://ivanamihic.com//files/kewipuxiv.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/fukemekisojonigubo.pdfIn PDF document text
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/1ff2ef130bc4ce014ce7b200ebd29149/79566637029.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/67c7f6e191d7699c78970577fc18c4ce/jopixezikazojedomazo.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/61145284552.pdfIn PDF document text
    • http://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/vunumomejezu.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7d3345d4b---nesesiwofekirefakit.pdfIn PDF document text
    • https://www.hausbootgeiseltalsee.de/wp-content/plugins/super-forms/uploads/php/files/257b10412438kacuissharucnd/pinisal.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/57074043179.pdfIn PDF document text
    • http://portalinmobiliario24.com/uploades/fckeditorfile/90282000566.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/19490494396.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/a2dfff9eaecc631a880799ff80ad8703/71421358416.pdfIn PDF document text
    • http://floramarble.com/uploads/22473676045.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/sisutezibasuza.pdfIn PDF document text
    • https://12tiga.com/contents//files/43345060281.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/5nggefbog1ld7vj036dcnqbrhv/muzogubuxu.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/sozojosilutus.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_off0000f8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C2 19052 bytes
SHA-256: 7a242f9e49d9667f1d6a9390095a8fff862aacd28855c3741c6cc4463417d082
font_01_sfnt_off00012b15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B15 10492 bytes
SHA-256: 521b5a809fa6d8abf7d1724f92a79382c6000d06d64c660807f340aeb771320a
font_02_sfnt_off000142be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1