Malicious PDF — malware analysis report

Static analysis result for SHA-256 276096bf4aaff446…

MALICIOUS

PDF

89.5 KB Created: 2021-09-09 18:18:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e2d3180f4c709d8adb0ca2917778b811 SHA-1: e30d9d6f2e19e4680fd0f6d787a85363c38510f2 SHA-256: 276096bf4aaff446982965d2ae0fa9af9a7e995514c9e15eacea18ed12b2f7fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a link farm pointing to compromised WordPress sites, which in turn host other PDF files. These links are likely intended to lure users into downloading further malicious content or to engage in phishing activities. The presence of multiple external URIs and the use of compromised CMS uploads indicate a distribution mechanism for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/uplcv?utm_term=why+are+ads+popping+up+on+my+home+screen PDF link annotation
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16130c749741ae---kigovamaxovorugemeweka.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/2436086559.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ff7a21037---puxesonabinexine.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xumaduz.pdfIn PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/zaxaripotezulekanumokasap.pdfIn PDF document text
    • http://mhfmjournal.com/data/22/2/55/64/2544879/user/2788947/htdocs/userfiles/file/gatuf.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138dacf229f9---badugiletejekananikufok.pdfIn PDF document text
    • http://baohanhranghm.com/upload/img/files/sibexaso.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/nadulabokujagotolufukoz.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/fidezeb.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161375175e1c86---5534329979.pdfIn PDF document text
    • http://hawaiisushi.iorderfoods.com/uploads/files/75770073973.pdfIn PDF document text
    • https://powerliteaac.com/userfiles/file/18884540797.pdfIn PDF document text
    • http://klenderbio.com/upload/files/nukevo.pdfIn PDF document text
    • https://isleo.com/i_photos/file/28759108100.pdfIn PDF document text
    • http://abwalabamaave.com/uploads/files/44213877257.pdfIn PDF document text
    • https://bulendengin.com/upload/ckfinder/files/76064095037.pdfIn PDF document text
    • https://bczenekar.hu/files/file/gazideze.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/8114570675.pdfIn PDF document text
    • http://jewelry-shopping-city.com/uploads/files/202109050336494087.pdfIn PDF document text
    • https://thingstodobahrain.net/ckfinder/userfiles/files/39069102708.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/37986384491.pdfIn PDF document text
    • http://jornalespacoaberto.com/app/webroot/datafiles/editor/files/lokip.pdfIn PDF document text
    • http://hansungidschool.com/userfiles/file/kamosonosukezufanudikava.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_off0000f5af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AF 11024 bytes
SHA-256: f10c21fb3eb84f4e00258b9b6919aa5aa7e59ed0197af692072890884f866895
font_01_sfnt_off00010eec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEC 18620 bytes
SHA-256: 9f2871ee66f88c45fd810e4f0b73d8857bd0c649b0455f301d3806b27c388ff6
font_02_sfnt_off00013fc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1