Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bb51cff380c871c…

MALICIOUS

PDF

74.1 KB Created: 2021-09-19 18:04:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 723c998118cdfe93b4d69d38d6334322 SHA-1: 491ca37c1b8e61af72bd070e902b8e402ce471c2 SHA-256: 5bb51cff380c871c5992e291bb193580679631ab6d4749b4efc56d951d2a9447
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The PDF structure and embedded links are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://vibanghanoi.com/uploads/files/vanupoteziwuveraxokarigor.pdf In PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613037705e155---35060292332.pdfIn PDF document text
    • https://maggies-handmade.com/UserFiles/files/79902239737.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614261267aed2---87957480341.pdfIn PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/radukuzebikov.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/popidugaxokiratulitisadu.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/mixujopozipiwipuzukuretos.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021090708544159.pdfIn PDF document text
    • http://herborgthailand.com/file_media/file_image/file/vawepiwapaj.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/81425966505.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/duguvekubiju.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/63301224649.pdfIn PDF document text
    • https://fu-ko-property-agency.com/webroot/editor-uploads/files/dusofotuwokox.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/74298242697.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/fevamoredawexit.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/2b5e46ac68fbfb02627d94d9e8f632e0/matemazawoxadolasazojez.pdfIn PDF document text
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/84502589853.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/zemevuxivele.pdfIn PDF document text
    • https://kingwrapcarspa.com/upload/files/fevefevevubigoxukolaf.pdfIn PDF document text
    • http://aprt1day.ru/file/nopuniradorow.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/52736704098.pdfIn PDF document text
    • http://gurgaontaxi.com/pa/trainstation/uploads/image/file/relukovekigovo.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///5791071593.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=timer+java+codePDF 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_off0000bf79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF79 17244 bytes
SHA-256: 62610c68a94b2a881f531064d066cc151d1b4fdebe92adb35769871c2cab01da
font_01_sfnt_off0000ec24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001043b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043B 10272 bytes
SHA-256: 56a06d27e6be0bcc8f5a7a52f3ca0235e53eefcb97a574fe8885638e169c7999