Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbae91844f4b1274…

MALICIOUS

PDF

83.5 KB Created: 2021-09-16 19:10:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d797bc7c39eb8011727510a6acf718ef SHA-1: 164794b680536f1a14e5329b11a2064643378ceb SHA-256: cbae91844f4b12743cbf0d9308e9bb442e1db94095e1659293f3ef71dea5dc0c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links pointing to disposable hosting or potentially compromised CMS uploads. The embedded URLs suggest a phishing or malware distribution scheme, likely involving redirection to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://smidgel.ru/uplcv?utm_term=android+1+csr+2 PDF link annotation
    • http://shangyi-pump.com/uploads/file/132032116384.pdfIn PDF document text
    • http://a-b-i-s.net/layout/bilder/file/76876054438.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/46823554296.pdfIn PDF document text
    • https://hitpoint.tw/userfiles/file/16305196581.pdfIn PDF document text
    • http://nebovsem.ru/app/webroot/files/files/35070950387.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/24845012090.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/6432574544.pdfIn PDF document text
    • https://estoniapools.com/contents/files/zewikododitafomozir.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/f26cfb5833079d189493a73ccab154c3/50890669385.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/67513176740.pdfIn PDF document text
    • https://textosl.com/upload/editor/file/39225452434.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ae4934329---xakorimiru.pdfIn PDF document text
    • http://pokebarslo.com/uploads/files/96659646437.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/91231730914.pdfIn PDF document text
    • http://smartpaintingplus.com/userfiles/files/58256644944.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/resew.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131072a74776---75554076085.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109120341319339.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/lejonadapazukuv.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/tabulawoxu.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/wagukasovabelev.pdfIn PDF document text
    • http://qazaqbanki.kz/data/content/files/30344086065.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_off0000e30a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB1C 18212 bytes
SHA-256: b7148f5d51feedfbbcd7ec4e479fd0e52bad97f5ef518618992fe4746be64b0d
font_02_sfnt_off00012a10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A10 10080 bytes
SHA-256: 39894087a44d4f0438d4fde7fa7fef6514b341503c05f0839f50edda167d83e8