Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcb8fd1b375c6b8f…

MALICIOUS

PDF

84.8 KB Created: 2021-09-09 04:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 91d63d0abf9ab9a6699753b50ddc0d44 SHA-1: 15b77d2f6f61bd4c95df6dca83ee4e89cc0c4141 SHA-256: fcb8fd1b375c6b8f774b5efccdf5089181a4386eb1696a9c1ab3bda2824cd522
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, several of which point to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cfaegaianascente.pt/portal/userfiles/files/vutorevilukofawaxepesar.pdf In PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/161323547332b7---98889397726.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/14ad7dd32911ea0a8901d914d3209eb4/befezili.pdfIn PDF document text
    • https://hamzsabegi60szallo.hu/UserFiles/File/jopiribijisevu.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/161385bf864e9b---rafidojuruvanupuwunepap.pdfIn PDF document text
    • http://dailynewsodia.com/assets/ckfinder/core/connector/php/uploads/files/67588325874.pdfIn PDF document text
    • https://huuphongplastic.vn/uploads/images/files/20816176793.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/14436057582.pdfIn PDF document text
    • https://thepainter.asia/upload/files/42618212373.pdfIn PDF document text
    • http://mtegl.wsystem.sk/userfiles/files/wimaviduzogum.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/he9sr0inikpoe60sgjrd7jgr2e/803584353.pdfIn PDF document text
    • http://ge-mak.com/files/55123901153.pdfIn PDF document text
    • http://professionalcatererspaul.pageindia.com/resume/cms_files/files/55710376058.pdfIn PDF document text
    • https://x-software.cz/data/file/movevumuxaxiwubimenen.pdfIn PDF document text
    • https://caraudioshop.ro/mm/file/58423277558.pdfIn PDF document text
    • https://mklaassen.nl/images/file/tativutogotureliradesaje.pdfIn PDF document text
    • https://carlojans.com/cms/file/60521519710.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/xemojaxon.pdfIn PDF document text
    • http://debten.net/UserFiles/File/ruwipemizivupusex.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/figipor.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/zaxodigiw.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads/files/202109031948495145.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/vivigu.pdfIn PDF document text
    • http://gucaoyun.com/uploads/file/011706093510.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/23544426051.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=kolamavu+kokila+full+moviePDF link annotation
    • 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_off0000e49a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE49A 19188 bytes
SHA-256: 0652818db4c22f8bc6d97757580cb420b387c15e5914fbea707cd4a0c335ae88
font_01_sfnt_off0001166b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1166B 10152 bytes
SHA-256: 9015ebed7cbcc34915f90b3421d2c12914939c7dc5a4b411bc8b084f5eb1983a
font_02_sfnt_off00012d25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1