Malicious PDF — malware analysis report

Static analysis result for SHA-256 137c33a4b49ab19e…

MALICIOUS

PDF

84.8 KB Created: 2021-06-26 22:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 5c558ec9b77ce57f5f700dfd3d1f0374 SHA-1: e734ce24c80b58457b2233daf0b623fd11b3b43a SHA-256: 137c33a4b49ab19ecf3517763c0b474aacf9d0dddac0208b45ee2e7247e25e26
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories or disposable domains, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document's structure as a link farm is a common tactic for directing users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://10glazsikeyrosa.ru/file/zepopevo.pdf In PDF document text
    • http://raiders71.com/clients/4/41/4134020f2f298c111575624a380fabfc/File/86703474746.pdfIn PDF document text
    • http://darienhigh69.com/clients/866565/File/wepivirip.pdfIn PDF document text
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/67b2ad3da7da36b1e309c055d08b02f0/nikujemurevivukego.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1919cd3c8---717803730.pdfIn PDF document text
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/160842c20bfaf5---kidukolesuzalotewopet.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/sopitatevodamejufinitiwa.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/h7u3o6g1hfie5mla4s9gnfn7f1/piferu.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/45d69af78061b750291f1d694bfb1b29/28072438679.pdfIn PDF document text
    • https://arte-salon.ru/upload_picture/9358113244.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/golutozuzal.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1609431c1364b6---gowamekafibefonu.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/xumefe.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608029bd23d0f---piberixojajuvasom.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/8177026867.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/t784mk1us6hum4ftnne5si2bh2/9054783215.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/hn4715ojbuj5qlset4i9jppsj4/82938887459.pdfIn PDF document text
    • http://www.kymkarajok.net/tiedostot/files/rasikikulan.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f050c01d5e---52176901902.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b732a83e2c6---48176086895.pdfIn PDF document text
    • https://whitesal.com/data/images/file/1145_20210517044919.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8a72c1275---kifukogofupug.pdfIn PDF document text
    • http://cunningham-reunion.com/clients/7/73/7399477c88ef979e1ad3ac38e42cffcc/File/90014645306.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607626597c829---kupezuzibekikiwafuvaxa.pdfIn PDF document text
    • http://mspchicagolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/diwufafoxevolewevemutupok.pdfIn PDF document text
    • https://www.ideaklinikbursa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f20783fa8a---tofikomebubuzotub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=how+do+you+remove+a+toilet+seatPDF 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_off0000e94d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE94D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10164 10660 bytes
SHA-256: 0cedaf588a843dee901ccf6466ca62fc266bf0a1d8d209415a98b776d439bf46
font_02_sfnt_off000119dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119DD 16828 bytes
SHA-256: 58d75b911c47aad40c64977e43c61eaa211cc2714e1c9567ad9fd2794a1ba8dc