Malicious PDF — malware analysis report

Static analysis result for SHA-256 87368fad2e2a4d67…

MALICIOUS

PDF

73.6 KB Created: 2021-09-15 09:47:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 98b8faa7b35799a307d0f376c2eba62b SHA-1: 97f99ae6ea8d30099b9d39519b0587722edd39f3 SHA-256: 87368fad2e2a4d67f088dd0f13170261ac98e9e934f7d8081bb0490125c3f03e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous URLs pointing to compromised WordPress uploads and disposable hosting, suggesting it functions as a link farm to distribute malicious content. The presence of embedded JavaScript, though not explicitly detailed, is a common method for PDF exploitation and redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://nomylo.ru/uplcv?utm_term=aurora+store+android PDF link annotation
    • https://smobiil.eu/userfiles/files/febarigozomodo.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/8588569723.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134336668da3---55478373763.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1614037e8c2eed---39186061756.pdfIn PDF document text
    • http://andrenickels.de/ckfinder/userfiles/files/dikodo.pdfIn PDF document text
    • http://baracenter.be/userfiles/file/4963221600.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/5e4s6e9bn2v0h4jdrbl3fhbm3n/daroxitapopupes.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/buvolimimerurukiwikija.pdfIn PDF document text
    • http://tuvanthanhlapcongty.biz/upload/ck/files/8234560218.pdfIn PDF document text
    • https://csn-alliance.com/data/files/muduvapil.pdfIn PDF document text
    • http://hansungid.com/userfiles/file/38493124940.pdfIn PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/66265475364.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/19109249525.pdfIn PDF document text
    • https://dynasty888.com/image/files/20210904_182416.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/75639728723.pdfIn PDF document text
    • http://imoroz.by/upload/file/jasenax.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/25466974111.pdfIn PDF document text
    • http://www.syrahresources.com.au/application/third_party/ckfinder/userfiles/files/80482355857.pdfIn PDF document text
    • https://europartner2.pl/uploads/waradosuzuvitula.pdfIn PDF document text
    • http://snkpost.com/fckedit_file/file///20210909_18_33_47.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/dupufame.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/77120876057.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/72613756992.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/kanezu.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_off0000beed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FF 16488 bytes
SHA-256: fc9607ee0cfd694b73ac4ece8814f763aeb79082f8effd113bceaffcde82c27b
font_02_sfnt_off000101af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101AF 10276 bytes
SHA-256: a5a11115d94b18d5bb8d5ed6bc57566930886717e2701f32d3d896f0ed8e889b