Malicious PDF — malware analysis report

Static analysis result for SHA-256 77a865796660f2f7…

MALICIOUS

PDF

76.5 KB Created: 2021-10-06 20:57:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 272a14e7fcfb799676ba8543ca976723 SHA-1: 87eb07226a567090ac48294d80e031d65cec3744 SHA-256: 77a865796660f2f70746d6248915331a0daf8bd9b69dd3c0bbe20422cc4e548c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://wastran.ru/uplcv?utm_term=how+can+convert+excel+to+pdf PDF link annotation
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/645c6fa6b12a8be7ed49c59cd56ad0af/3227995350.pdfIn PDF document text
    • http://manhchenang.vn/webroot/img/files/wokawijidazik.pdfIn PDF document text
    • https://gencshow.com/upload/ckfinder/files/kukubezidavazugazer.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/62077475225.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16142e0a1e621e---leridubewunikawog.pdfIn PDF document text
    • https://arerp.kr/data/file///kobikakujiradesejibu.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/2237949812.pdfIn PDF document text
    • https://exclusivelimoservice.com/ckfinder/userfiles/files/xatijesedirof.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/39274860100.pdfIn PDF document text
    • http://imprezka.2kc.pl/Upload/file/97043996334.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/15327764711.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614110e12edc9---51265068997.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/eiuudb5erlg7fnnptpdruia51k/41727550921.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/lujejibibofejap.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/81530044752.pdfIn PDF document text
    • https://ice-group.pl/userfiles/file/92562413678.pdfIn PDF document text
    • https://dhesient.com/media/vijasu.pdfIn PDF document text
    • http://euroteam.vn/ckfinder/userfiles/files/87791932960.pdfIn PDF document text
    • http://www.satunatc.ac.th/ckfinder/userfiles/files/12022873774.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/meviduwoxubatusipawu.pdfIn PDF document text
    • http://qapoll.com/2015/vat/upload/files/jetavolefon.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1613545f32268f---55517185338.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/76224316061.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_off0000c723.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC723 17480 bytes
SHA-256: d7675af0568b85359397a4dde95f5a2f63c3d53531f7a34493231155f4f9a9d1
font_01_sfnt_off0000f40f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40F 10596 bytes
SHA-256: 8937d01c0af99921e596fc114f25fb373c412d5f0822476be71b6774b2ab6364
font_02_sfnt_off00010c6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1