Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b18e8e3dfddaaff…

MALICIOUS

PDF

77.6 KB Created: 2021-09-18 07:00:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: c5e7f1f74b11dc969a444ceebb4bcf68 SHA-1: 6559a1391ee079861a309f4bd75355c9981a30cd SHA-256: 4b18e8e3dfddaaff209c743b72bfb9dc1f6c017eddcff4ac4bb073beb46515fb
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many pointing to compromised or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 http://casms.org/atts/news-files/file/21242385098.pdf In PDF document text
    • https://gestcargo.com/uploadfiles/file/63526844589.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/zeruzimoxonidadobifin.pdfIn PDF document text
    • https://tidurmalam.com/contents/files/fawuken.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021090115185273499.pdfIn PDF document text
    • http://thegioidahoacuong.com/uploads/image/files/42381593861.pdfIn PDF document text
    • http://ecole-belair.com/ecole/file/39873323359.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613139d1c9102---gewoduseg.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/razugusakabelisezik.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/bilemodijifunenemuxitijog.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/10562729427.pdfIn PDF document text
    • http://danchrisjewelry.com/userfiles/file/36946969537.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/jbvqas6m8f9hv60m0ot2cn5386/29807548769.pdfIn PDF document text
    • http://gachtrangtritranvinhtin.com/gachtrangtritranvinhtin/Images_upload/files/legusokixej.pdfIn PDF document text
    • http://traslochimontalto.it/userfiles/files/fefefuvukimumudegufo.pdfIn PDF document text
    • https://cicasoftavukatwebsitesi.demowebsiteleri.com/upload/files/6827415339.pdfIn PDF document text
    • http://pzhjintai.com/upload/files/wodibasusav.pdfIn PDF document text
    • http://zbirozskepodzamci.cz/userfiles/9625359784.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/84996123085.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138463409503---xojaxusotuzuso.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/2563403297.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=watch+football+free+on+firestickPDF link annotation
    • 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_off0000caff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAFF 17536 bytes
SHA-256: f811bedf248fe118af990bd034e8674adc65c829ba5967484f3124303749d47f
font_01_sfnt_off0000f8bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D6 10656 bytes
SHA-256: 2f119b8c9b572650a07b5b5f94c58a37e685236a771e120ad0810536baaf7c05