Malicious PDF — malware analysis report

Static analysis result for SHA-256 86936914e71b4d5b…

MALICIOUS

PDF

82.0 KB Created: 2021-05-28 04:28:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 4d2d1af10feb8624460dd6f1d9676046 SHA-1: 5bd349618346a19c0b6b3b673ebf9912ee30b057 SHA-256: 86936914e71b4d5b34cc4cd43f709f8ac16bab893ea4b6418f3079d60992a849
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a ClickFix paste-and-run lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://chcial.ru/uplcv?utm_term=miracle+box+crack+2.89+start+button+not+working PDF link annotation
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/f785ac735d783e0ee4d18d20920a38e2/86396100147.pdfIn PDF document text
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/93002646ae16ac37710b5f67c199d7cf/xemidikikumevolupis.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/vedesowaz.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16078a133dc96d---60749696737.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/15345911362.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607a765498162---33246386711.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee2145e20c---jakiduketufinagam.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/c7032945bcbfbf0eaf391f94d4cf5ddf/85670895656.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075182270889---16209995690.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2dfe43fe5---57559157910.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608a79005d9b8---raboretekiwat.pdfIn PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/tovezum.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn 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_off0000df0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0F 5852 bytes
SHA-256: 9dec6b5bd43338909adef6f32d25e45b411851c325f65610442a15f2ca377452
font_01_sfnt_off0000f323.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF323 1908 bytes
SHA-256: 57743e0843cb64de294e2c8128c0cbbe01bc6fae718101501fd124026965c57a
font_02_sfnt_off0000fc74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC74 11548 bytes
SHA-256: 1cbe4cdb386a9578bea037951e2cdde406921c586be2df2456f07dacb8336a29
font_03_sfnt_off0001241f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1241F 16060 bytes
SHA-256: df1d2c903cabdf2976887e260da0b25217edeb5ce2b71f315001024534e8e210