Malicious PDF — malware analysis report

Static analysis result for SHA-256 43133e1b4fe8af99…

MALICIOUS

PDF

81.8 KB Created: 2021-09-16 16:00:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9d92b08ad5bc916c7f42825373bab771 SHA-1: b8babefa23eb65ee29c6b478159b0f50b5702baf SHA-256: 43133e1b4fe8af99ea7fdea086a41dac8b754ef8408d988b9c03c9231fe2a3f0
96 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 websites that appear to be compromised or are using disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristics suggest this PDF is a link farm designed to redirect users to potentially harmful content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://denizlihorozu.com/resimler/files/81100556171.pdf In PDF document text
    • http://lnianemarzenie.pl/userfiles/file/51806468494.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcc172d35a---lufebuwineruxubalopigose.pdfIn PDF document text
    • http://www.espace-hotelier.com/ckfinder/userfiles/files/kilabirujedafodakovu.pdfIn PDF document text
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/rexoporewoxi.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210911163458.pdfIn PDF document text
    • http://aldobini.it/userfiles/files/94342030438.pdfIn PDF document text
    • https://energooptima.hu/upload/File/77201732056.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/42846569999.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/94052484392.pdfIn PDF document text
    • http://cnwt.mgo.cool/upfile/files/2021/09/07/vomewububagesazu.pdfIn PDF document text
    • http://mathcountsoutreach.org/userfiles/file/35869510685.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161344f9b497c0---wumilozan.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/99349477722.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/12586409222.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/lovuxelura.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/91646621253.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/48930386641.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nivimebupike.pdfIn PDF document text
    • http://symbolfoods.com/files/file///17064350081.pdfIn PDF document text
    • http://huabulaw.com/uploadpic/2021-9/file/2021091603502773499.pdfIn PDF document text
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/72415134921.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/6jpd218greq8rt9tnev8453bkk/wabite.pdfIn PDF document text
    • https://hoongnau.com/upload/files/92446548600.pdfIn PDF document text
    • http://qualityspices.in/ckuploads/files/fijoxezak.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/zagakitutenezupol.pdfIn PDF document text
    • http://inimtrento.it/userfiles/files/nenezidekuwavujijuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=pixel+experience+galaxy+note+8PDF 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_off0000da30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA30 10804 bytes
SHA-256: 88cce560fb519b994587db489f5b7200ad26b5040f6e3a5ca98056b1f612a0db
font_01_sfnt_off0000f34b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34B 17644 bytes
SHA-256: 5f0cf6caa88b7b7590e0a0fd7fb577da88dc3ea265c0cf312752a4c824d46047
font_02_sfnt_off0001210b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1210B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1