Malicious PDF — malware analysis report

Static analysis result for SHA-256 481901bc81d3384a…

MALICIOUS

PDF

88.9 KB Created: 2021-07-26 09:19:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e26055cb1a20e49324778f5b7f5eb32c SHA-1: 90a466fe1225a270185de9fa03c1d7c27a5df21a SHA-256: 481901bc81d3384a5be2a3638674b185dcf9cd869d3707b4e25be54d286c2bdf
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised websites, including one hosted on a raw IP address. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests a deliberate attempt to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://anhuifan.com/upload_fck/file/2021-5-1/20210501080957651653.pdf In PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609840f23d60c---56148441353.pdfIn PDF document text
    • http://kantoromega.pl/userfiles/file/76519660080.pdfIn PDF document text
    • http://rheinmotel.com/userfiles/file/zufafavomepur.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/35440494552.pdfIn PDF document text
    • http://trlgpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/62375384035.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbb42ca31d---vuzesi.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e7b752958c---puxavobalupizenotasozewus.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/11ec32d9cdbf522cdb9761d846d207c6/mexilejisevibizijel.pdfIn PDF document text
    • http://azizavacanze.com/userfiles/files/95023429881.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/237ae0d90804741bce6841fd854ab018/45288827868.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b93dce3df8e---874974296.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/16079ba72d4fa1---72036710297.pdfPDF link annotation
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16086acfc0c43a---memufuzizitikizorede.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160787314dfc43---68991082807.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/paxopusikasuxo.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/kovifujixofedexolukaxaka.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/62e9a41eeacfe375e354a697a3ee9946/nerefifosuludasupuxozedeg.pdfIn PDF document text
    • http://jingtianlawfirm.com/images/uploadfile/files/vixizu.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/75p8b6rnot3903dsp068hb0a46/60827561905.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/50122849954.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/6453cb8790258f6ef2c2b5d8c6ac712f/8829953318.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/13325087397.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=vocal+star+vs+800+reviewPDF 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_off0000f521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF521 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D38 10572 bytes
SHA-256: 71998ae85de9083844f318334e2c8834cec2b170511e0659bd07e654dfbbf910
font_02_sfnt_off0001258c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1258C 19396 bytes
SHA-256: c04d4eee89eb90de3e53c53576d52a6602fdd07efc7703b22ac7269cb83b0f17

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