Malicious PDF — malware analysis report

Static analysis result for SHA-256 81550b8df1e2487c…

MALICIOUS

PDF

73.9 KB Created: 2021-06-29 02:05:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1a80144c628c8021c3edc5cde9cc6d07 SHA-1: 0ce7aec84b6d6b9263b739f403d28bf7c92e2e9c SHA-256: 81550b8df1e2487c8be8b547a422d02b81dd76768e17b71157af32868b0261f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous embedded URLs that point to external sites, many of which are hosted on compromised WordPress installations or disposable domains. These links are likely intended to lead users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/f47a3f4b402b25a1ca7de10352e00b88/furumebunugomowabekukug.pdf
    • http://wajl.net/img/file/2021621165728.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0d63634b---pefabenimovaxusinodusajo.pdf
    • http://furniture83.com/upload/files/63707926626.pdf
    • http://otoozevran.com/resimler/files/78547523961.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/67f3hfrolshcat52jkkmgk123a/4868828255.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b48f2a8b9---potamidasigef.pdf
    • http://motorlustor.net/userfiles/file/gitaniriwepojerati.pdf
    • https://ferado.vn/userfiles/file/xafesefuvo.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/f2e8487725cfcef498286d3017ea39a1/wezivosilalo.pdf
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/sjorimdesad9i1c4igbf7dvvq1/57519543839.pdf
    • http://nebo52.ru/uploads/files/65590865822.pdf
    • https://skyzoan.com/cake/beta/userfiles/file/9809312028.pdf
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e847d3e4ba---14882701934.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb455492ff7---36895249309.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/ae2ef738a1e0a791539756181b4239cf/lipozemoninowolep.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4dfd8b1bf---poputenawilevi.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/7091738b4dd322ae3c517cc6815f4604/98217935869.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b69bc2f5d---33832522104.pdf
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/fa19489f0620e6244264da93c1ecf3bc/lusegofazetufuwi.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/c02c574998e3a433616a6557b8d0619f/lerisonolikoxefipuk.pdf
    • https://bcbc3399.com/upload/files/tanonesedezepomuwode.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac6b85d24c---38899187729.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/77db4df328c626945c7276cadc6115ea/28142427988.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=link+is+up
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c44b.bin
b5b88118ee3665b37e6ae5da33c8ffa66030994652e7bdfba9a17fdb230e2b3c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC44B 9736 bytes
font_01_sfnt_off0000d991.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD991 16792 bytes
font_02_sfnt_off0000f1a3.bin
910f7d78a80eb0496564e35035be01660d566fc851c130dee26f34a30e0ef8e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A3 15920 bytes