Malicious PDF — malware analysis report

Static analysis result for SHA-256 252b62cf0defa516…

MALICIOUS

PDF

73.8 KB Created: 2021-09-12 13:53:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 74d8d213ea62267f7aff6184200bcf33 SHA-1: 85c1b682955c0ad1912ea4a1737ef72286ab4b80 SHA-256: 252b62cf0defa51688be5e1c710a96d1115e6eb54fd0be87ad1b5c7a0e1e8bdd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The primary purpose appears to be directing users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=srsroot+5.1+apk
    • http://hotelpenza58.ru/ckfinder/userfiles/files/19571340039.pdf
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613619d6c6c7e---50473237444.pdf
    • http://www.jacenter.org/js/ckfinder/userfiles/files/xajezaxisov.pdf
    • https://thaiahpa.com/flash/files/bofevof.pdf
    • https://www.comperat-89.fr/ckfinder/userfiles/files/lalogotigesajisadas.pdf
    • http://hferrynetworks.com/FileData/ckfinder/files/20210909_762D39569BE55703.pdf
    • http://studiotecnicoligioni.com/userfiles/files/61297964590.pdf
    • http://hysansam.com/fckeditor/userfiles/image/fesodojezelidevim.pdf
    • https://htapigroup3.com/contents/files/sulamar.pdf
    • http://www.hussco-steel.com/husscofiles/files/24982812254.pdf
    • http://xmst.com.vn/app/webroot/uploads/files/nomubovikexutamerasuxa.pdf
    • http://sintjorisparochie.nl/userfiles/file/90403715450.pdf
    • https://cbconsulting112.ca/userfiles/files/24852204311.pdf
    • https://sunnyvale.com/wysiwygfiles/file/sudugevulasarigimegum.pdf
    • http://aranykoronakft.hu/userfiles/file/76512031643.pdf
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/18803601518.pdf
    • http://nexxosrealty.com/userfiles/files/zonul.pdf
    • http://asustainable.com/global/file/wixurekukemipe.pdf
    • https://maviet.vn/upload/files/17824393495.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/ofkdtud6h7etufh7g1oik0sin7/87845274302.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/rbr68m374v9ktdd9ar9rjja12f/55132045298.pdf
    • http://arablift.net/userfiles/file/pazixojuz.pdf
    • https://xedulichhaiphong.vn/images/news/files/50392471871.pdf
    • https://perfecthospital.org/FCKeditor/file/91029758612.pdf
    • 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_off0000b851.bin
5efb2b574af2155f6c2c3da754fd8f6612b3d0877ecc36b5bef68a3bcf611a42
pdf-font-stream PDF embedded font (sfnt) at offset 0xB851 18604 bytes
font_01_sfnt_off0000e954.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE954 16792 bytes
font_02_sfnt_off0001016b.bin
43daa914ecf5ab417a4455cef3ed0a3817d72626ffdaaccb60aa0bc0bfc06c95
pdf-font-stream PDF embedded font (sfnt) at offset 0x1016B 10288 bytes