Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba8b4062ecc8ac1c…

MALICIOUS

PDF

70.4 KB Created: 2021-09-25 10:51:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5489017ca5b951b9366f64d0266089f0 SHA-1: 3aabb7b6dafcbcb411c43b105df672af8805d6d6 SHA-256: ba8b4062ecc8ac1cf0cbaba845e86e5e9b106e3e636caa4567620305c7643d7f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that function as a link farm, directing users to other PDF files hosted on various domains. Several heuristics indicate this is a link farm on disposable or compromised hosting, with ClamAV detecting it as a phishing trojan. The ML classifier also strongly flagged it as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://inks.bg/userfiles/file/doposasusasofebigoda.pdf
    • https://angelsforwarriors.org/userfiles/files/valerobijugemusesif.pdf
    • https://solucionaesp.com/ckfinder/userfiles/files/24318959465.pdf
    • http://zhatuogz.com/uploadfile/file/81527186441.pdf
    • http://www.ondebiz.com/userfiles/file/gozarimitiwev.pdf
    • http://robwalker.net/fckupload/file/41871815229.pdf
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210905_F797203138959A44.pdf
    • https://www.sophrologue-nimes.fr/upload/news/files/kogalalidideputajet.pdf
    • https://hyundainhapkhau.vn/upload/files/defevotakefipufufanodivap.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb8b3202c---31955920168.pdf
    • https://escolaalfa.com/userfiles/file/gupobonesatefewawelabujev.pdf
    • http://systempro.kr/userData/board/file/35703255312.pdf
    • https://djennebeads.com/nbloom/fckuploads/file/62629659822.pdf
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/warogafuvituka.pdf
    • http://ardechetendancebrut.fr/userfiles/ardechetendancebrut.fr/file/20661030734.pdf
    • https://alternatifhirdavat.com/upload/ckfinder/files/larubinigufemug.pdf
    • http://nsdadventist.org/FCKData/file/18402306698.pdf
    • https://harom.ro/files/file/68370417763.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327da56fe67---3066539504.pdf
    • http://msslink.ru/userfiles/files/54830297138.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614b84e82abec---wised.pdf
    • http://orzo.cz/uploaded/files/92765323141.pdf
    • http://euro520.net/userfiles/file/16321516391493876836.pdf
    • https://booknowrentalimo.ch/userfiles/files/zavoderez.pdf
    • http://gearcon-eng.com/file_media/file_image/file/winutexubutafamiliruwimef.pdf
    • http://8njl.com/userfiles/files/58296163623.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=set+it+up+watch+online+with+subtitles
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1bd.bin
89b695574c85dca3d517dd4cbecadb6e74ab8d64e4e41ee8b1600660be90c308
pdf-font-stream PDF embedded font (sfnt) at offset 0xB1BD 10772 bytes
font_01_sfnt_off0000ca4c.bin
f20b9b085b4f17b3df061aa18719618df744fb9ba9aa195468810a3277a6fa82
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA4C 15660 bytes
font_02_sfnt_off0000f224.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF224 16792 bytes