Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7982792d6c2212c…

MALICIOUS

PDF

85.3 KB Created: 2021-09-23 04:08:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3d4c00d5b2878bda025729ec5e34cddf SHA-1: 91a871972d55247c6ed1d84a1bbd8ce574d093eb SHA-256: a7982792d6c2212c54f00603fb83fe3d407cff7352954a234fc410123a28ecbc
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/xuwuvikabonafasamevenirog.pdf
    • http://hdg-gmuend.de/userfiles/files/zagasalimisesovados.pdf
    • https://agrimal.pl/userfiles/file/burofotuvuzek.pdf
    • http://rydelko.eu/userfiles/file/gekuregaratesuzijikawimak.pdf
    • http://knowleangling.co.uk/ckfinder/userfiles/files/sulezuwuvexuzosokag.pdf
    • https://krzczonowice.pl/gfx/file/vesukiripoziwedobemoji.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137b001370af---50582011943.pdf
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f13b348919---viwomiruliwoladoxef.pdf
    • http://samnakthodrahassob.com/userfiles/file/bewewaluzefeboxuk.pdf
    • http://xn----8sbfhu6ab4bqv.xn--p1ai/userfiles/file/xejixuzisevegaw.pdf
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/buniwazavozezewufu.pdf
    • http://growlink.biz/userfiles/file/pumixuwavuvomanuw.pdf
    • http://sinsg.com/files/fckeditor/file/sufevubodebege.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1614143879f2aa---givirelagivid.pdf
    • https://rusepress.com/uploads/wysiwyg/files/97303939562.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138304ba13be---97236069055.pdf
    • http://moristas.com/userfiles/files/toluzozagowadodixepi.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/6204b7155c90bd32725a6444caa5e945/fenofoj.pdf
    • https://edubox.mn/uploads/users/0/files/durobuwalerabaweta.pdf
    • https://www.mnogotrop.com/ckfinder/userfiles/files/28894634502.pdf
    • https://gjbuyerbroker.com/userfiles/file/jufodufanumupubim.pdf
    • https://exam11.menapoint.com/app/webroot/upload/files/5411729908.pdf
    • http://aapltd.net/userfiles/file/tesijefiloven.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+do+i+find+the+dcim+folder+on+my+android+phone
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e744.bin
1d9d3f8d95e4464d2dd646567a27efda8e71d3242abe5f383e9da1dd059fa582
pdf-font-stream PDF embedded font (sfnt) at offset 0xE744 18408 bytes
font_01_sfnt_off0001168f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1168F 16792 bytes
font_02_sfnt_off00012ea6.bin
4d4450da9960180d6819573458ce90e6d3b07e4f1cf02862f554a8da17679722
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EA6 10908 bytes