Malicious PDF — malware analysis report

Static analysis result for SHA-256 91bd57ff8637120c…

MALICIOUS

PDF

78.5 KB Created: 2021-09-10 05:30:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5562b6c6f951690c3ff78496a6de28af SHA-1: 4d806661b4d6f7760de9a2b826aaf68536417a0c SHA-256: 91bd57ff8637120ca2ddc0d594f19e707e1776fc8b33e8b94f39a9bbd53095e2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the structure is designed to host many links, often with UTM parameters, suggesting an attempt to manipulate search engine results or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://huntic.ru/uplcv?utm_term=dragon+city+private+server+ios PDF link annotation
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a07155369---29837910876.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/47819495895.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/witagivukobekufos.pdfIn PDF document text
    • http://alvitraders.com/files/5144031665.pdfIn PDF document text
    • http://phayaotechno.com/UserFiles/File/64993977945.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210908173129.pdfIn PDF document text
    • https://thegioidongphuc.net/ckfinder/userfiles/files/teledugowowafaxuzu.pdfIn PDF document text
    • http://africareview.in/userfiles/file/66180444685.pdfIn PDF document text
    • https://xn--90aoja6ahg5ds.xn--p1ai/uploads/files/60643344868.pdfIn PDF document text
    • http://sbkf.org/files/files/losigorabuzeve.pdfIn PDF document text
    • https://serpavenger.com/ckfinder/userfiles/files/repadavelizadoduxevanive.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/53436870011.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390eb7923fc---57032896452.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/kigotasubesoj.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/44732639979.pdfIn PDF document text
    • https://dienmayminhchau.vn/uploads/news_file/86206141880.pdfIn PDF document text
    • http://wish-pharma.com/upload/files/87517843363.pdfIn PDF document text
    • https://un7un9b3rl1pa7-99.com/contents/files/wulepanapoz.pdfIn PDF document text
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/dazatawozi.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/41300050434.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a167e87d1---sazisupa.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/bowatorobepunejinu.pdfIn PDF document text
    • http://shinyoungvalve.com/userData/board/file/76224028042.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_off0000cbb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB7 10684 bytes
SHA-256: 08bc4e60ca028b2812b53a4d908b544b96521eaecf73820fc43cfbd6d011c3f2
font_01_sfnt_off0000e465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE465 18480 bytes
SHA-256: 3f25d756a73ed40cb020d6e4d4c800684631fb2848269f9f6d62e4228cf50635
font_02_sfnt_off00011489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11489 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1