Malicious PDF — malware analysis report

Static analysis result for SHA-256 efc77e6e2bbcc9b1…

MALICIOUS

PDF

83.6 KB Created: 2021-09-05 20:07:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dd87bd0b9d94479447bc5c5599806e30 SHA-1: be95a5681b85f5ba1137c60d580600ac2ed5d453 SHA-256: efc77e6e2bbcc9b1def0d5ca21260c7b5a5acd44a9bb01ca3596ad3a1f766c05
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDFs. This pattern is indicative of a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7a967c378---nejotusebuxizos.pdf In PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/658c0c38febd9a4534649d64215564ba/72863009991.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/53229422272.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608398dc71a62---6385351832.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b23a9cc87b2---wawizexenemanof.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080bd5822535---74155353853.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/15665707460c2780782a77.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/26191994172.pdfIn PDF document text
    • http://snnet.kr/board_pds/fckeditor/2021/08/file/jepaxinuvofi.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/lkorigpt5dueq8q746q0gv6s20/97114808446.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/57115790134.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fbfc0c20cf---gavazeluwogufivosavomi.pdfIn PDF document text
    • http://cybernet-ap.com/UserFiles/File/wodimijazife.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///jelamirokekumo.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/cc43638b8124d9382e230ffd70fa2163/ranasisob.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/020102c1feeeb5573a3d564dc5476a2a/92192909974.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/47110688756.pdfIn PDF document text
    • https://zapret-rf.org/web/img/podborky/files/nojokafanusunireg.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/golijamiran.pdfIn PDF document text
    • http://1984wnhs.com/clients/2/25/250e0aaa51dad033202e6c34d8602b4d/File/zaferizerukigibutoj.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fa42a20c43---gepibe.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc60f9c3ee---fages.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/mutavapilusazomixug.pdfIn PDF document text
    • http://e-restauracion.com/app/webroot/files/uploads/files/64183218857.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/xojekubelorenaporiwabavur.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160f6336688f38---mutapenabekenitubowep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=campaign+plan+sample+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_off0000e1d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D8 17896 bytes
SHA-256: 8255da18d4f0f704f7cc92739ba389ec9f334dd616aae3232a750fe2c6b98095
font_01_sfnt_off000110af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128C6 10556 bytes
SHA-256: 05ffe6b46ce8d70c0e4db917ee300878a543953aca7c09585c4fb77f7516f2c8