Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ea1333d53209aa7…

MALICIOUS

PDF

74.5 KB Created: 2021-09-26 05:03:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fa207a5238562e937df0968597ad75a5 SHA-1: 5cf832be009cfc10d4787c3ac4f68ad3818db7e7 SHA-256: 8ea1333d53209aa7b831b106946a5a7f60240e9d1b2e44848630fc31760c34b0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier strongly suggests malicious intent. While no scripts were directly extracted, the structure and URL patterns are consistent with SEO spam or phishing lures, often delivered as spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://chcial.ru/uplcv?utm_term=discrete+mathematics+notes+pdf PDF link annotation
    • http://ivelinabozilova.com/userfiles/file/59938710181.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/xokagi.pdfIn PDF document text
    • https://jamuiboe.com/webroot/upload_media/67850055618.pdfIn PDF document text
    • http://buydecor.ru/uploads/files/resimuwizugokanobixaful.pdfIn PDF document text
    • https://nppgursaraijhansi.in/ckfinder/userfiles/files/vesukumad.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a3b1eec2a3---fekewavo.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/wiwekikek.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/kimukopoduroporitefu.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210907_012524_181.pdfIn PDF document text
    • http://52fotki.ru/ckfinder/userfiles/files/32903901846.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/xidexasi.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b339a8415---30053144899.pdfIn PDF document text
    • http://teleinwestor.pl/userfiles/file/xoxoserex.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614cfdca466da---jesalilukagifilaxiderigaw.pdfIn PDF document text
    • https://amoslodge10.org/ckfinder/userfiles/files/zufewuzebopadale.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/46557938300.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/63535531169.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/subax.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/71176059433.pdfIn PDF document text
    • https://jungleflightchiangmai.jungle-flight.com/Uploads/files/wujigotijagefinu.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/99641458630.pdfIn PDF document text
    • https://sanagustin.cl/files/xugoxusikazomopivi.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/jedas.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/10835880024.pdfIn PDF document text
    • 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_off0000ba49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d260.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD260 10840 bytes
SHA-256: 5e948209520eb775ff379e84a6dac74ee7caf259b501247b1afe9d5dae6951ce
font_02_sfnt_off0000eb31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB31 18908 bytes
SHA-256: 6838c60154503fa1f730955cafc078ba7455a6bf12921d951e4376bf530b0fbf