Malicious PDF — malware analysis report

Static analysis result for SHA-256 b336822cdae5311d…

MALICIOUS

PDF

76.0 KB Created: 2021-09-24 12:01:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bad4a2a6f8eaafc14b34748945a84ae0 SHA-1: ffe52b93c79a123fcac54949625601f16e812832 SHA-256: b336822cdae5311d102994a59ccdea24baad989d020dd1edefc140e24eda2729
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, with multiple URLs pointing to potentially compromised or disposable hosting. The presence of a link to a WordPress upload directory further suggests malicious intent, likely to host or redirect to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161413d84474b8---35126374302.pdf In PDF document text
    • http://clinical-pain.com/pds/userfiles/files/17482287479.pdfIn PDF document text
    • https://bnovum.hu/downloads/32908052497.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/refevufoxefusav.pdfIn PDF document text
    • https://serihosting.com/calisma2/files/uploads/43360012753.pdfIn PDF document text
    • http://westhollywood.ilovepokebar.com/uploads/files/jigupelibiveloxuruzuler.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/18853291780.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/turonasaniberesanase.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/kojizorabat.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/6483923629.pdfIn PDF document text
    • http://hsaltsj.com/uploads/files/80819467948.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/e97f96ddf774d933675f88bf701261be/giribib.pdfIn PDF document text
    • http://khamranghaiphong.com/upload/files/gelanezikofujesu.pdfIn PDF document text
    • https://peoplehelppeople.net/uploads/File/51093067320.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/15330302820.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/837068448612f03c238214.pdfIn PDF document text
    • http://cserepakcio.hu/xdata/file/12511654571.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/bd64c82cc4ef2a66cdbae511d09464d4/fukosuruluxavuralakil.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/wemuwedowakap.pdfIn PDF document text
    • https://rajaunited.com/contents/files/87780108073.pdfIn PDF document text
    • https://subhagataguesthouse.com/userfiles/file/femepilujeroroxosukoradif.pdfIn PDF document text
    • http://chochosanencino.com/uploads/files/6100457566.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/fotizedumakobotivesobavop.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147fc314c462---53752429165.pdfIn PDF document text
    • https://tattica.byespresso.com/app/webroot/files/upload/files/9269442185.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=free+pets+in+among+us+iosPDF 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_off0000c5b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B2 10624 bytes
SHA-256: 850caf11caca35096f3768df384024cd567e474c6c7de1c24b3ee289d276bcd1
font_01_sfnt_off0000ddf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF8 17272 bytes
SHA-256: 9ec4c3717299df5e4db4ed13c481798512c1bcd14b4f895d287ab50f7864b4da
font_02_sfnt_off00010a40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1