Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5a3eb4177d69477…

MALICIOUS

PDF

79.1 KB Created: 2021-09-17 22:18:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e934bca430c60aa228322371c91dad56 SHA-1: 7fcf47caa7b73c4041c28d73f25706ca6c611a93 SHA-256: c5a3eb4177d69477879c76a7e99c8bf48559b72b0a6536ef49cdaa3061919950
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to compromised websites and disposable hosting, characteristic of a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the document's purpose is to host a collection of links for SEO manipulation or to distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://irlanc.ru/uplcv?utm_term=summary+of+the+giver+chapter+20 PDF link annotation
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161376eae7c76b---67829391382.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/vorux.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/selexe.pdfIn PDF document text
    • http://barbusci.it/maisUserFile/file/47644797471.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/29363887243.pdfIn PDF document text
    • https://terrebleue.org/userfiles/file/70163162845.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/14002492361.pdfIn PDF document text
    • https://zohopin.com/calisma2/files/uploads/44743111750.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/xufanixo.pdfIn PDF document text
    • http://synthecinter.com/userfiles/files/firim.pdfIn PDF document text
    • http://moscreen.in/cmsfiles/file/28257177601.pdfIn PDF document text
    • http://leguido.net/files/zenefi.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/32966881973.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343e261d95d---89941957294.pdfIn PDF document text
    • http://beta-rc.com/upload/files/196311750.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/nunefewobibuvemeruvi.pdfIn PDF document text
    • http://ch-bovi.com/upload/files/2144056306.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423b8ad8ad4---bozipuzejuvidoj.pdfIn PDF document text
    • http://ozdermusavirlik.net/userfiles/file/35188187792.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/takulopapelug.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613e535246cf3---68180450949.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_off0000d078.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD078 17672 bytes
SHA-256: dbd0a5da909724226881689fe14a902a5079b0b11b6686a9ddebb34e242d887a
font_01_sfnt_off0000fc85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001149c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1149C 11208 bytes
SHA-256: 32f318244756ce9b339258f36b171814d19127761e2a2b653b2cfe219d45b8b0