Malicious PDF — malware analysis report

Static analysis result for SHA-256 8157e9fbe053036b…

MALICIOUS

PDF

79.4 KB Created: 2021-09-01 04:51:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 529711809c143a228c12fac4f3b7c008 SHA-1: e4047b2543384977e9247e8360633f9b37641691 SHA-256: 8157e9fbe053036b38b1029c0026e1c5f23e4afda5d21328de61b88b561cf789
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. 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 0.9984

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 http://articolo17.it/siti//usr/foto/files/61923392470.pdf In PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210816/file/16290900931167.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/nr3l1ui0llu4mpm6euqko4lg62/fupizuwixaloderi.pdfIn PDF document text
    • https://khanikango.in/file/18523910899.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/sobikilojefeliviz.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8c292d3848---kuketavedimigegazewo.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/7cd6374145742f59ab9118d40e22e468/7813191054.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1609422e67d1da---31043895620.pdfIn PDF document text
    • https://elger.cz/fckphotos/file/sagomel.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/44435803422.pdfIn PDF document text
    • http://homeopathyhongkong.cn/files/gujusisiwepawejamowosewe.pdfIn PDF document text
    • https://mbzgogo.xyz/web/img/podborky/files/16857444566.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/todiwuxowovikisezifimol.pdfIn PDF document text
    • http://plymouth-logs.co.uk/ckfinder/userfiles/files/rufek.pdfIn PDF document text
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/41681497111.pdfIn PDF document text
    • https://pabxlg.com/userfiles/file/7615577610.pdfIn PDF document text
    • https://gofropack.com/wp-content/plugins/super-forms/uploads/php/files/fc28f668831730ccda47a45d86c94c14/30745219227.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8ac60e5f9---fuzefeforabopafi.pdfIn PDF document text
    • https://confetti-seasons.ru/upload/files/xigal.pdfIn PDF document text
    • http://smartickgroup.com/userfiles/jopumipi.pdfIn PDF document text
    • https://jancsoalapitvany.hu/ckfinder/userfiles/files/70158697914.pdfIn PDF document text
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/folam.pdfIn PDF document text
    • https://ibextrail.com/editor-images/24868921083.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/20623798246.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=excise+duty+in+tamilPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b86e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB86E 19724 bytes
SHA-256: 180674d0028ae39cfdc8fea1409e31b0519e7e5804f0b1ec3e85c4f9391a8c2e
font_01_sfnt_off0000e84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001005d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005D 16328 bytes
SHA-256: 53f0afd4f5c4932d3f5d1577168871fc735c25f821741fb74535cca9fdda17c3
font_03_sfnt_off000116b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116B4 10612 bytes
SHA-256: 897c2f0e6907848e79fb69ea8c77b6860f8879be049239cf482127ba26d29677