Malicious PDF — malware analysis report

Static analysis result for SHA-256 991ae1de9666af71…

MALICIOUS

PDF

85.0 KB Created: 2021-09-03 19:51:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3ef1d82e448a22ab0ea016169d9f1be8 SHA-1: a0e286d419395970bc73f2ac784391373b228716 SHA-256: 991ae1de9666af71990e593bb74a32f81dddd704afe9f7012d762bf735e8aaa8
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised CMS platforms or disposable domains. This behavior is characteristic of a link farm used to distribute malicious content or conduct phishing attacks. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://bukhatirhomes.com/userfiles/file/8200411535.pdf In PDF document text
    • http://secureyun.cn/uploadfile/file///2021081320013060.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/26c8c80cd4fcd39785c6c7e77afd9f8f/11934181871.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160790ee3178db---tusolipop.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/d115028b16dfade42dceb27126362e9b/43866936729.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/3220534058.pdfIn PDF document text
    • https://www.wizzfizz.com.au/application/third_party/ckfinder/userfiles/files/soguxomase.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2a1c76a19---23682153318.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/8d3b846040f72a59094a69f10a474195/49621297095.pdfIn PDF document text
    • http://vinhthuan.asia/upload/files/rixaw.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ee5d192e87d---manowakuzifurotubodupidon.pdfIn PDF document text
    • http://reklamavysocina.cz/UserFiles/File/zifinezusowukomenarera.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/12872587061.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c2c5d91e1---mikoz.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/wezotesabosikivuniguv.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210607114558_n878fh.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/67299883452.pdfIn PDF document text
    • https://togeltop.net/contents//files/37736555505.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/ee679e8e0aa0df66aad439fa856693eb/kunixulisiwijumutu.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/58852728354.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/54091831519.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/f86fd9a9edc950a54113188a6032b1c1/pakakugenovejese.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/gozif.pdfIn PDF document text
    • https://triosms.com/userfiles/file/10293617493.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=polymeric+insulators+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_off0000e5aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC1 10996 bytes
SHA-256: 4c82611e82bd27091833b8a947e0c4a2ae793432334cca32c04220bead7c2dc6
font_02_sfnt_off00011756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11756 17932 bytes
SHA-256: 7ad1a6db62df2b19daf244f91a5737929775e94b388cff52ec920184afbafedb