Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c8e2ff631b31e68…

MALICIOUS

PDF

85.2 KB Created: 2021-09-01 07:02:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3d18a0cd6539e812d1e5df7f9c91d460 SHA-1: ecb0c1f091da2c9d1aa9b4ba222a1933d19224e8 SHA-256: 2c8e2ff631b31e68e05fbc574e710d08bbd970e91954583719885993bced9766
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external PDF files hosted on potentially compromised websites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly suggests a phishing or malware distribution campaign leveraging these external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://stylekd.ru/files/wilozaloliwumuwalusi.pdf In PDF document text
    • http://bajcsidavidfoto.com/_user/file/lamisavefikekilipa.pdfIn PDF document text
    • http://designbeginnings.com/upload/file/tilikazenuvukavelak.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/welegekifi.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/73062e08274fc8d1518ff8638d3dcd6e/foxawo.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/87415629871.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/954eef70b470aca5827c0a4bd4ffb038/46332255198.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/fukibaxezuruniwuzeperoz.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/aee3312254dc95044611569eba72dec3/duxin.pdfIn PDF document text
    • http://odontoflash.eu/userfiles/files/guperalenikosamadujeg.pdfIn PDF document text
    • https://ladangmimpi.com/contents//files/2379049161.pdfIn PDF document text
    • https://grnca.org/img/files/files/77878367888.pdfIn PDF document text
    • http://phuongdonggolf.vn/app/webroot/uploads/files/xiwusonagowow.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/1a4b3e304804b61335bfc81037452471/butir.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/12048111df32880189f8a7aa5233ff07/lomomuvololatasomamafaji.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9939b1ec99---67317368687.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/74945618301.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/risawogazisizidonanupu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=grid+square+mapPDF 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_off0000e6e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E0 10468 bytes
SHA-256: bef6b1b319d20d386ffac58dedb6b3b361866902db371aa2e7cdbd36fdc7d425
font_01_sfnt_off0000fe73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11685 18444 bytes
SHA-256: b5aa3cf888a33413d81a795937b4325dfd9b3a3c92b83b3c2e468a647ff9304b