Malicious PDF — malware analysis report

Static analysis result for SHA-256 87dc1c9be07267fc…

MALICIOUS

PDF

83.9 KB Created: 2021-09-03 05:57:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 2b4e1d1ce356f58d76a59323bfbc1391 SHA-1: 467c41d0aa3b3cfc1970f737b153c622b5f500ed SHA-256: 87dc1c9be07267fc94df2e494770a1784f26bde6fa7a3172d766aa4e9230d51c
192 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a callback-phone (TOAD) lure and an urgency-based lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 9

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://ahcxdq.com/uploads/file/020547259104.pdf In PDF document text
    • http://tingyi-bnb.com/CKEdit/upload/files/tawolivuxiz.pdfIn PDF document text
    • http://portamarioarchitetto.eu/userfiles/files/lizuzumidigibezuta.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/99eecbfc4ff88f9976bd17fb31722029/59908137160.pdfIn PDF document text
    • http://casier-a-bouteilles.com/file/zoruro.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/06/20/file/libisat.pdfIn PDF document text
    • https://dm288.rs/slicice/file/melaluvatonulan.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/0ubhlmc066s1uicucki80ji69i/funomidikaxiziloneba.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/acbf809bcf8fca49b1d4a2456a8fc591/43492978552.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/zefetufamofixe.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/zoxujovoxegibowolinizexuj.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/3s24ahccl39muj883gjlrpba0n/41212809818.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/a04cca407e093e39a11ad19bfa8a377d/kovudiranavuzisikajizo.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/nixin.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0234b0c0a---8897995964.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/a51990eddd44c65a24ae9edd6b30a761/91386203506.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/27684935102.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16083c11a170d2---lunozabela.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/fobizofedokimedoximimif.pdfIn PDF document text
    • http://etpatatietpatata.com/userfiles/files/kamawuvu.pdfIn PDF document text
    • https://avonsteel.com/UserFiles/file/51277146641.pdfIn PDF document text
    • http://sjmhospital.org/files/js/ckfinder/userfiles/files/metaguta.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160dd9a0bdd30e---59574297189.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c457ad6badc---navagemivodoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=religare+care+freedom+brochure+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_off0000e43e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC50 17704 bytes
SHA-256: 8cc59bad1d0067b3109b42c8086a0b90217d4af0c0b4470b898dc115ef2d6663
font_02_sfnt_off00012978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12978 10984 bytes
SHA-256: 08df23423bd3a670082effc8a95cfb1fc2574fa5c9fb55e02a5d2e50523ec0c9