Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7de58cd49de3cca…

MALICIOUS

PDF

82.0 KB Created: 2021-09-07 22:19:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 581ff464bbea5ff3465dfb2f77b33c83 SHA-1: a283df539fd6229e4338cb9ca2ae57574b560e54 SHA-256: a7de58cd49de3cca893830e182367271fc33dee4120c1ed05f0bdcc99f4c4e8b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to distribute or redirect to malicious content. Although no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest it's designed to lead users to phishing or malware download sites, likely via a spearphishing attachment delivery method.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://aklond.com/UploadFilesfile///2021050707381368.pdf In PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/ib40m63bmqv5t4p7ibhes4kue7/810807675.pdfIn PDF document text
    • http://ltptech.vn/uploads/userfiles/file/lujaxataxapusifipo.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/umoa0g01npvudjomja1lvd7hd3/vefid.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/bifab.pdfIn PDF document text
    • https://stratasphere.online/userfiles/file/58012410763.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/lejimamelunuludimev.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/wamuxafonotumunasosakapu.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/e40a485ccf2b20e626aff8b91db32d11/megelap.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e55457fb5---4998763923.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/35637001318.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/40279462369.pdfIn PDF document text
    • https://hunghiephuylog.com/upload/files/36902509973.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161219ebe361e3---nibigasudogowonavo.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160803e706cbc4---xerudujegokufebulot.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4f7df3463---ziwimekutekasuzelox.pdfIn PDF document text
    • http://www.kmclogistics.com/wp-content/plugins/super-forms/uploads/php/files/81806b089218d044366eea8441a2f9ea/28373364834.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/tuxugoreviv.pdfIn PDF document text
    • http://pomodorolennep.de/gfx/userfiles/files/70990380175.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/bb95532b49f8d5794675884c81dceb8f/62759353486.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16121cfbd43d5f---tosuroxofejefol.pdfIn PDF document text
    • http://thebranchoflife.org/clients/3/37/37a84c4c47f147f839b5d5a44bb1b86c/File/94718751617.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/rutodu.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/251630037751.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+play+arpeggios+on+guitar+pdfPDF 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_off0000dbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFC 17224 bytes
SHA-256: 3ba78750b3d7ba832f3b68ab22ddf0b415424ead421a2a52fbdf21eb06515c7a
font_01_sfnt_off000108ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AC 10964 bytes
SHA-256: 84c18f3602cdc195ff258367ea4f780b13243eb513595d898f31aeb61c560f77
font_02_sfnt_off00012218.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12218 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1