Malicious PDF — malware analysis report

Static analysis result for SHA-256 19b9f65a998a1465…

MALICIOUS

PDF

72.0 KB Created: 2021-09-08 18:06:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7355be041cfa81a1fb5cce9f164582f1 SHA-1: 2acb1e78bd07d1716108481abb2de4da38650ba9 SHA-256: 19b9f65a998a14655e962e5397b41d252682210b8f14aa574545440e0dd8d406
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to potentially compromised websites or link farms. Heuristics indicate a 'link farm' pattern, suggesting the PDF's primary purpose is to redirect users to malicious or phishing sites. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://coretry.ru/uplcv?utm_term=operating+system+concepts+pdf+github PDF link annotation
    • https://duragloss.pl/userfiles/file/44954650216.pdfIn PDF document text
    • https://derfo.info/resimler/files/jagiwipigivajipun.pdfIn PDF document text
    • http://atek-ent.com/upload/file/60036231121.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/baselibi.pdfIn PDF document text
    • https://luatsuavina.com/userfiles/file/59670108052.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/50820262242.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c3417380a---newol.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/64449276138.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/sejalokup.pdfIn PDF document text
    • http://dietgame.net/admin/fckeditor/data/file/20210905224632.pdfIn PDF document text
    • http://hoitruyengiaocodocvietnam.com/uploads/image/files/44993652741.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///202198215795505.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/gajadugimibogixe.pdfIn PDF document text
    • http://studiosiriosrl.it/userfiles/files/70175267304.pdfIn PDF document text
    • http://sinoorchids.com/image/file/gezas.pdfIn PDF document text
    • https://reformedgeneration.com/userfiles/file/65641428905.pdfIn PDF document text
    • http://apex-architect.ru/images/file/72018421526.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/u5b40ngnqk1p3topkjutubg0os/99049481682.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/wezesopokeminevavirizu.pdfIn PDF document text
    • https://insp.biz/img/file/jusufikotamazulugerim.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/37044143143.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/ejs4scq5r6pqflmq5lc3l1mcq5/piwepagopagafawita.pdfIn PDF document text
    • http://chemtron-vostok.ru/media/file/49973990627.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/vedaworazuvoteliz.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_off0000b8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8E3 11400 bytes
SHA-256: 6cbd41d6de406ff2dfd797c313d4c0cfe449310511f21276e0204b82f7417cae
font_01_sfnt_off0000d33a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD33A 15168 bytes
SHA-256: 6afe8b6c0a783b78a0faaac3a1eda2f6fba95d74eff1fa5cae0463e14b191dbe
font_02_sfnt_off0000f9fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1