Malicious PDF — malware analysis report

Static analysis result for SHA-256 198d2be1baf43e64…

MALICIOUS

PDF

71.7 KB Created: 2021-05-27 18:06:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: d58b90c201bb8016b6c93b4d91b42aea SHA-1: 243b526618e60b32699d9b449ca3c74a4507be46 SHA-256: 198d2be1baf43e64c2fa121479d299ee00ca3804d20c0282071913034c491624
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The document body, though heavily obfuscated, contains metadata related to wkhtmltopdf and a mathematical phrase, suggesting a potential lure or distraction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ildiko-szepsegszalon.hu/userfiles/file/redumerutisavebikut.pdf In PDF document text
    • https://atamergranit.com/userfiles/file/lenatogufozaxaboxekotujot.pdfIn PDF document text
    • http://www.apsetedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607abd1ed5974---foduzexirofelir.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607593f63219a---2693744711.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/neneperabasuvakakatutavex.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/16091b31e9f855---binivurigeb.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c5eb8229f---jigasizolikatilenunojipu.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606c928141d2a---21251645469.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608132ea0b9c1---10718710908.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/jekc4a722g22tiif3kjt952046/62948900619.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/9dd8fe947e3a7a2ab8dae4634617ac96/vegopivewimuwuvaxu.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae35bf325f---92264914045.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1fff890d3---54530389573.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160871f358c27f---81609080906.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/c6f476decb3ee52565e5cfddcfcc4ec7/totumogegapomilomib.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=todos+los+divisores+de+1261PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d87e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD87E 4956 bytes
SHA-256: e3c09ad345f029cc095251eec07f0726b1106b76d52f869a648a3f3775e5dd17
font_01_sfnt_off0000e97b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE97B 11820 bytes
SHA-256: c47914b4d8e2bc3454d4fb6616388012003ea08e15389f06bca2db85b36db010