Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8bc88f3d9f82344…

MALICIOUS

PDF

72.8 KB Created: 2021-09-04 10:00:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6d1a8639fee9265e646b4776f22a6065 SHA-1: 716086d7c186eae1d764c910e03889d7f57ca0e4 SHA-256: c8bc88f3d9f82344db55efc4603485d181ff00ef4e01c395b32b32e43b17b95b
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct hosts, many of which are hosted on compromised CMS platforms or disposable domains. The embedded URLs suggest an attempt to direct users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://facade-metal.ch/ckfinder/userfiles/files/10073359801.pdf In PDF document text
    • https://rowadalbyt.com/userfiles/files/42294101690.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/fc90e078d2011fecf034cc0b6d630e55/silekaronomigonotegedis.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4951beaa3---88289907741.pdfIn PDF document text
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/jopeditu.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/54634111489.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079d18ba73f8---najumiginijadomakumamam.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/rufegona.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16095c025285ae---62692548163.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/savakivajuvemilizaresiba.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/a37360943ec34a57360539294f65e213/bonuj.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/cc96182606aae38a3cab9eb49a5d7336/85401090106.pdfIn PDF document text
    • http://dblbtech.com/userfiles/file/kezoba.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/73073188483.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/18550467d7c564632b561214aab078e7/fezizut.pdfIn PDF document text
    • http://www.udelimpa.es/ckfinder/userfiles/files/75731450517.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/a30a90b1d3c61f03617a3e7b2173b603/difasufalebix.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/0b9ef465d7d7575b2d1b41cbdff4fec7/livexobinuzutu.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/68522170803.pdfIn PDF document text
    • https://harrisitalia.it/uploads/file/ledusi.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607181562add5---ludowir.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16087af4bca38d---29346944273.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/dutasatitu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=accept+file+input+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_off0000b8ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8AB 18000 bytes
SHA-256: 48f001aeb796a8c043969b81a367020812cc0804aaf92d558a342f9ce486a9ca
font_01_sfnt_off0000e720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE720 10144 bytes
SHA-256: cc61b2e49657ad5c7b385b136c97a2780753d1a053b4385f34a656e7826638f7
font_02_sfnt_off0000fde1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1