Malicious PDF — malware analysis report

Static analysis result for SHA-256 e81d09cc50ee52b5…

MALICIOUS

PDF

70.8 KB Created: 2021-09-13 00:59:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4568ce0efa8e1842985c3b4eaafcc3e2 SHA-1: 60a54570fd07984aa848dcd9cabc37f72ecd3c5d SHA-256: e81d09cc50ee52b502c2e30984a2129b0095dff4e4a1096b4308fc87a1f973db
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The primary function appears to be directing users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://coretry.ru/uplcv?utm_term=derivadas+pdf+ejercicios+resueltos PDF link annotation
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/228bf393a6e558d6a70f21d0e5edf1dc/posedajinaxenewolowadavar.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/xinekebilanimekizelezed.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/mudiniv.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/36389273047.pdfIn PDF document text
    • http://thepducphat.com/upload/files/59631107695.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/lupujazuvisafumifumi.pdfIn PDF document text
    • https://celebicatering.com/upload/ckfinder/files/81755459088.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/xagivunakegifik.pdfIn PDF document text
    • https://mangallagn.com/images/file/fojazumomaxoz.pdfIn PDF document text
    • http://allycatering.com/userfiles/sepaxire.pdfIn PDF document text
    • http://trip-sale.ru/userfiles/file/jodoxuxujuvanunavol.pdfIn PDF document text
    • http://kino-cosmik.ru/sadm_files/nejetatujof.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/29368914393.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210904143125806914667.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1631232240.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613361875e2b1---16808089813.pdfIn PDF document text
    • http://insei.eu/userfiles/files/lumakimos.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/43739956599.pdfIn PDF document text
    • http://varosom.hu/userfiles/files/57994602561.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/rilusokadolisuv.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613de302b7fd8---kolajapijowumonowog.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9f5b30d8f---mekikexup.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/naxuvakan.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_off0000b394.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB394 16184 bytes
SHA-256: 04ae59748ad46291ab0466830814c25d5699bb3ffed7af4bb80b1d2c1d7d1257
font_01_sfnt_off0000dc93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC93 10808 bytes
SHA-256: b08911edf996770cb567fd5a91af9fc2e200a89403f75eec2cf8a45fff82c696
font_02_sfnt_off0000f5a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1