Malicious PDF — malware analysis report

Static analysis result for SHA-256 88174ec3361b3cc9…

MALICIOUS

PDF

71.5 KB Created: 2021-09-25 22:11:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 91566dd00e54100bbfd12d28c248747c SHA-1: c9f739d64cafeccb9dde8f9e6b79e3ee75e1ee1a SHA-256: 88174ec3361b3cc981c51f77dd9b2cd5d0cf10a7ff6649efef1b0017b6635509
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://irlanc.ru/uplcv?utm_term=moto+g5s+plus+security+update+2020 PDF link annotation
    • http://hoangle.vn/uploads/userfiles/file/71132074943.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16146e3b813a8b---paxotomolunozil.pdfIn PDF document text
    • http://eis-pieschel.de/UserFiles/File/lekuwinojo.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/46175354554.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/30858383348.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/91908123194.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/754a883d3ae4b72398776e931edbef97/nafovizabotinowi.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149a38bd3c49---mevifebuf.pdfIn PDF document text
    • http://phukhoabacninh.com/images/files/13199586309.pdfIn PDF document text
    • http://hotelniagararimini.eu/userfiles/files/valajodote.pdfIn PDF document text
    • http://www.tahi.hu/ckfinder/userfiles/files/wikanifewomibik.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/20383571776.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/7f71ca5eeeb70e3bfa465294c8e73218/limeratavekeripevabilok.pdfIn PDF document text
    • http://ptairsupply.com/userfiles/file/firega.pdfIn PDF document text
    • http://starroadchina.com/userfiles/file/niboxovosodozes.pdfIn PDF document text
    • http://webminmax.com/userfiles/file/boritovanedil.pdfIn PDF document text
    • http://yey.uw52.com/upload/files/sazajipirobusimoxido.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/16683866059.pdfIn PDF document text
    • http://viorina-deko.com/images/file/lolixaxonirise.pdfIn PDF document text
    • https://gyvatukai.manovonia.lt/images/files/robimeputod.pdfIn PDF document text
    • http://pressvaluation.net/FCKeditor/editor/filemanager/connectors/userfiles/file/73408316986.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/90959720619.pdfIn PDF document text
    • 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_off0000b084.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB084 17760 bytes
SHA-256: 65ceb25fbad067a9da097dadcb0f7fdb58250bee8f3080cf1193486098772da8
font_01_sfnt_off0000de0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0F 11168 bytes
SHA-256: 5d82e4a142c4d7ee9194b9a6b6fadf003507ac1980a9600a69ee02082d3122e6
font_02_sfnt_off0000f846.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF846 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1