Malicious PDF — malware analysis report

Static analysis result for SHA-256 b76892a2a4210c6f…

MALICIOUS

PDF

79.8 KB Created: 2021-06-27 22:02:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 91e483317774e27cfcea440c34159816 SHA-1: 84ae02bdbd010dd77bfcfb9e06e9ab9da943b4ac SHA-256: b76892a2a4210c6f62178ef96b8fd026cd6011980e9a25329860af356de5d2c6
176 Risk Score

Malware Insights

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

The sample is a malicious PDF, as indicated by ML classification and ClamAV detection. It contains a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The malformed stream length heuristic further supports its exploit-driven nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/afa243e678756a4792a9a9ba391c6e38/73291971330.pdf In PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04f69c9464---liruxemiparuvapetaxa.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/f69b14e5lttl9a9omj3pge46fe/wokovaka.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a641ea484d4---zibuvofirusosekeleg.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/73602207867.pdfIn PDF document text
    • https://businesslife.com/content/file/75816737046.pdfIn PDF document text
    • http://topas.lt/userfiles/file/87911074708.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/29bd6609c5c5c6f711823de3a5f3fff3/pazotelupuzenilifinigij.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607a699832fbd---19246430690.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/nufuvonarotomoxut.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/c5f061de356232b787244d6a70aa428a/94172026276.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/57428538733.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/sudisur.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3c5ba1f2a1---pulugupinoloroj.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/9f4e0e8009b8398a44ddcf6ad265e805/rifajivekisafaburokox.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/dljkolmeter2ndfna8m6siv86u/64690621762.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/28927972904.pdfIn PDF document text
    • http://gocreate.termall.pl/upload/fck/file/varonoxujep.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609accb16b11b---ledipolewa.pdfIn PDF document text
    • http://musiclivemarsala.com/userfiles/files/83717524878.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/6pgbqe422alo6dug6h9qmg6pm6/panulebiwutekanobej.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/1785f37f3af1272db8ee556b7fa769d9/laxalofemeravevigoli.pdfIn PDF document text
    • http://dkmmotor.com/files/userfiles/file/bosedagimujafibudo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=micro+economics+notes+ba+1st+yearPDF 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_off0000d516.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD516 10644 bytes
SHA-256: 5c72289144d623cc9fba1fe92eb99794c9b697cb6d549947ea31a92cb4b9ee69
font_01_sfnt_off0000ed9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9B 16508 bytes
SHA-256: 69d94a504365aaa1465cede21ab72f2c67dc4f8feed1b9ed9aebd6241937f905
font_02_sfnt_off00011830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11830 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1