Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f6438c73770cc17…

MALICIOUS

PDF

70.1 KB Created: 2021-09-29 07:59:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c706dfa5ff17f12a4e4ff00ee0a55b4e SHA-1: 028d0f8761e84219aa7d762811984b4b6e54cbe2 SHA-256: 8f6438c73770cc17a5ff28f16f57e55be2cfb93c0d1dd589dd685720f4dcf140
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what is inferred from the heuristics and URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://newabel.com/ckfinder/userfiles/files/8344230682.pdf In PDF document text
    • https://northcoteplaza.com/userfiles/file/81309101094.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f0600d739f---welatalemepaxazagodizabu.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/tevonanaz.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/gezedarijezikuzaw.pdfIn PDF document text
    • http://americasbestwingsbeltsville.com/uploads/files/fetufofiduza.pdfIn PDF document text
    • https://vnmmalta.com/userfiles/file/34245500166.pdfIn PDF document text
    • http://unicorn-furnitures.com/d/files/gujagafemuna.pdfIn PDF document text
    • https://oazapiekna.com/zdjecia/fck/file/ragenazorasuxunapibi.pdfIn PDF document text
    • http://contua.org/userfiles/file/zubotufetakibaperuvonirez.pdfIn PDF document text
    • https://stehovani-ostrava.cz/static_pages_files/file/dikedusadigovafuzaxagen.pdfIn PDF document text
    • https://hiroyoung.com/data/files/38440262039.pdfIn PDF document text
    • https://yauspeshen.com/ckfinder/userfiles/files/46459672107.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/8166222353.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/4e6cc363b71a32c92be117d3f3c98643/talakuzogukalezave.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613c4c021c0da---zipopiwedutidojeg.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210919135055.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/23963676428.pdfIn PDF document text
    • http://shanghaicruiseparty.com/uploads/file/52762953508.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161538d0eca781---genuradevawasez.pdfIn PDF document text
    • http://zima.italie-ubytovani.cz/data/file/tukajonudopepifimimab.pdfIn PDF document text
    • http://acelybio.com/upload/files/63997425500.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16146d097c33a6---85198226833.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/47r0cr915dehr8bg3vs5m40at9/bapodufivinepunawunu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=fate+and+furious+9+full+moviePDF 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_off0000b461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB461 14920 bytes
SHA-256: 99e5ca0d1bd01af81669ccbcfb96478cedacb42eeb87bee683d30edce97f2866
font_01_sfnt_off0000d9b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B8 10828 bytes
SHA-256: c1d9ee302b0b46b0711b3f496b935a78e2b7269b8fa7652d9b5d2fb755620c24
font_02_sfnt_off0000f2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1