Malicious PDF — malware analysis report

Static analysis result for SHA-256 2bfefd00165fb2ec…

MALICIOUS

PDF

74.2 KB Created: 2021-09-16 09:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 550c8295c14275ecb4250aa0c8dc941b SHA-1: 0fd3d37605e3468e549cc37213a1e1a78b4d72eb SHA-256: 2bfefd00165fb2ecceaa070d299781bb10e68c9a83ee87e0f51dfb7bad8701c4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS uploads or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a strategy to obscure the true destination by using many distinct, low-reputation hosts. While no scripts were explicitly extracted, the nature of the embedded URLs suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://synerhu.ru/uplcv?utm_term=android+viewflipper+swipe+example PDF link annotation
    • https://gloriamus.org/Uploads/userfiles/files/xamilagobevekemugikuges.pdfIn PDF document text
    • https://petrovsky14.ru/docs/files/mirunowobufetagiputulol.pdfIn PDF document text
    • http://fsanaq.com/upload/file/210906114957103252b4msdkr8f1pr.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/wudajovufinuseme.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/10889843207.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328dfc60a2b---22843358972.pdfIn PDF document text
    • https://edarky.net/data/file/malukajavijozopevojaxu.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/kafoteferewilo.pdfIn PDF document text
    • https://vieclamlaocai.vn/webroot/img/files/67422841249.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/22064589750.pdfIn PDF document text
    • http://goldmustang.com/files/files/sitegojopuxetugi.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/jllqm1amarbln9t211hqltv9o6/41991628772.pdfIn PDF document text
    • https://brukspec.pl/upload/file/lojitonikenupizedadupemu.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/52265733435.pdfIn PDF document text
    • http://vdi.vn/userfiles/file/tofalezidi.pdfIn PDF document text
    • http://kbinteriery.cz/userfiles/file/34529532370.pdfIn PDF document text
    • http://thietbiotovn.com/Images_upload/files/46293453801.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/lldmknocbkagt55uprj24436t7/35346628497.pdfIn PDF document text
    • https://qpshouse.com/upload/image/file/2461308221.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/molebatubazo.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/e76ae539e0c005333959fe9ad94a70bd/febizupunevozat.pdfIn PDF document text
    • http://elfast.ru/userfiles/file/89932217306.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_off0000bbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBF5 10796 bytes
SHA-256: 76acf1d62ec25cbf91a6004d24934e766ca3861d714b21c629ad9f6c864bbb16
font_01_sfnt_off0000d4e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF7 18032 bytes
SHA-256: 1271dcde5bad63f848ce828d91ae23aea2cc5b871f20ce144f06aed2b3fa1a08