Malicious PDF — malware analysis report

Static analysis result for SHA-256 72375bdf293b4dff…

MALICIOUS

PDF

84.1 KB Created: 2021-09-20 09:55:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6f07dca5346060154533e2ea96ec12df SHA-1: bfc343837e38bc5b4b5565ffaef8321cb8bf14fd SHA-256: 72375bdf293b4dff0fbfec1a6f68f39458f3da7ea1f5bfd51015ed13b0f84e8e
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript and numerous links to external websites. Several heuristics indicate these links are part of a link farm hosted on potentially compromised or disposable domains, suggesting a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=vsco+premium+mod+apk
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146edc4323dc---51453885373.pdf
    • http://ukicda.com/admin/fckeditor_upfiles/file/2021091900061680554.pdf
    • https://shidoremicrosys.com/media/56589591183.pdf
    • https://skvely-kup.cz/files/file/jaxiso.pdf
    • https://guruamardaspublicschool.com/userfiles/files/41318477506.pdf
    • http://algarestofos.pnh.pt/js/ckfinder/userfiles/files/24105415322.pdf
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16132d858542bf---96130451958.pdf
    • http://chiangmai-clean.com/user_img/files/jatekubatoxanosilo.pdf
    • https://mama-light.net/business_school/uploads/file/86908231100.pdf
    • https://igraonica.me/userfiles/file/fiwuxavimumaginofi.pdf
    • http://sushinamu.com/uploads/files/motovi.pdf
    • https://euforbiabulgaria.com/uploads/pages/files/85936412685.pdf
    • http://pneusmarene.it/images/file/xedubebuvuzijowubam.pdf
    • http://konferencii.org/web/uploads/assets/file/dowitepepami.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/1isagbs0r435r0dnvpftcgbj63/surimowamolatapiw.pdf
    • https://stepweystudy.com/ckfinder/userfiles/files/11766769177.pdf
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ac56399c5ab170f97364d2e62cfa81c8/vugabanuxowovovabopabox.pdf
    • http://fundacionecla.org/resources/original/file/wupiwofebifaxinuk.pdf
    • http://elvirajogsi.hu/ckfinder/userfiles/files/50428423586.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/sfjf1ks3oknfuhd5hbpfti3i01/55714549478.pdf
    • http://zentrumok.com/userfile/files/55058446829.pdf
    • http://www.vegagastro.pl/upload/file/38792340669.pdf
    • http://euro-ex.net/images/blog/file/49127841472.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/161302e32d289c---biwajo.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e45c.bin
60c3c4cd5c2f37868627fbb3c004a7616fd7cb4e567fc5f7631c45490310037d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE45C 10588 bytes
font_01_sfnt_off0000fc93.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC93 16792 bytes
font_02_sfnt_off000114a5.bin
0a42a6ca2954099b840a9e7e7f13cdd23ae6eac0cb9c8e179fb3edd4ba5f5b26
pdf-font-stream PDF embedded font (sfnt) at offset 0x114A5 17832 bytes