Malicious PDF — malware analysis report

Static analysis result for SHA-256 87ab1b4d5b4486d1…

MALICIOUS

PDF

81.2 KB Created: 2021-09-11 07:56:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 70e17f57eccd16a029f64f1fb390162b SHA-1: 0e50ebe6d430a4455c6754d58bfdf888f6229003 SHA-256: 87ab1b4d5b4486d11bf9f677f94c2519ab10c5ccc63466ff62f7d415d2086556
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be disposable or compromised hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, suggesting the PDF is designed to leverage search engine optimization and compromised websites to lure victims.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://synerhu.ru/uplcv?utm_term=streaming+movie+apps+for+firestick PDF link annotation
    • http://webinaris.blog/ckfinder/userfiles/publics/files/mirixari.pdfIn PDF document text
    • http://haozuowenwang.com/imagefiles/file/26982373421.pdfIn PDF document text
    • https://gibidesign.com/fckfiles/file/15376578247.pdfIn PDF document text
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/kobugup.pdfIn PDF document text
    • http://poorclarescork.ie/images/mosorer.pdfIn PDF document text
    • https://khonggiansachhanoi.vn/uploads/files/21973274209.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c265f4dc85---17168823073.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/756189d9dbe0142989843ccabe9fcfbd/89453600097.pdfIn PDF document text
    • http://salman-group.com/userfiles/file/redinunamosexuzude.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/62939843330.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/55551779783.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/rikozegefeda.pdfIn PDF document text
    • http://cafehinglung.com/uploads/files/56467220185.pdfIn PDF document text
    • http://kawana.tech/userfiles/file/rozemowijulelidafa.pdfIn PDF document text
    • http://goozzl.com/userfiles/files/wakadomuxotujor.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/16838478820.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/piwefa.pdfIn PDF document text
    • https://planningpvedh.nl/ckfinder/userfiles/files/didibepuputulipaxilurowe.pdfIn PDF document text
    • https://e-ceramika.pl/userfiles/file/kewidogexun.pdfIn PDF document text
    • http://munnarteabungalows.com/userfiles/file/58975187978.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf9c3b9958---kizowopi.pdfIn PDF document text
    • http://onyx-innovations.com/assets/ckfinder/userfiles/files/4271808423.pdfIn PDF document text
    • http://satakantaresort.com/user_img/files/63835264276.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_off0000d7a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A0 11012 bytes
SHA-256: 9339af7ff4d4ff5db8f1e99b0fc0e78591a554cdf3aef4f0a6a0f94a6cd80d71
font_01_sfnt_off0000f147.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF147 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10959 17696 bytes
SHA-256: f185d0bc42347bd58678ad30b7c2a8671f414b3d6c1527395e90bec2cfcf2616