Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f6f825c1c914d3…

MALICIOUS

PDF

80.1 KB Created: 2021-09-22 19:59:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 39d600d933edb1b7226f48016b46b6a5 SHA-1: 862a7cba3d3daa715c5ff4de82e3690d878c2780 SHA-256: d8f6f825c1c914d311721fe875c67b29ea3204864280a73e2658bd131ab1f7e2
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised CMS upload directories, suggesting a phishing or redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or download further malware. No scripts were extracted, but the link farm nature and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/3b94008aca440e1209df7ab404e8398b/30098974463.pdf
    • http://rs-entp.com/upload/file/munowepomuki.pdf
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/3819687670.pdf
    • http://sarkar.ie/userfiles/file/2225764761.pdf
    • https://bishopsalamatkhokhar.org/userfiles/file/wosixifujabaf.pdf
    • http://form4concrete.ru/pics/cont/file/gurivoxowojokatinuf.pdf
    • https://contabil-fiscal.ro/mm/file/jexobemijiragixupigejolug.pdf
    • http://apexibd.com/uploads/fck_uploads/file/18606608521.pdf
    • https://grupahatak.pl/admin/_fck_files/file/vapifasijalot.pdf
    • http://indyztyle.com/ckfinder/userfiles/files/16936329626.pdf
    • https://joebalogh.ro/imagini_ws/48562531258.pdf
    • http://eko-gospodarstwo.eu/files/file/loxosewanon.pdf
    • http://aedelsur.com/contenido/files/78875616455.pdf
    • https://horacebatten.com/ckfinder/userfiles/files/63034526994.pdf
    • https://bomando.bomsolar.com/uploadfiles/files/14943997680.pdf
    • http://strandedtattoo.com/file/78991569986.pdf
    • https://foodphotoshop.com/userfiles/files/kelivorametax.pdf
    • http://www.iciparis.ru/ckfinder/userfiles/files/91644750748.pdf
    • https://kabelkyaobuv.sk/editor_uploads/files/jobolewedo.pdf
    • http://babijie.com/upload_fck/file/2021-9-22/20210922222127559142.pdf
    • http://yachtales.net/admin/userfiles/files/20304042640.pdf
    • http://danieldesignpro.com/userfiles/xizisukatisetedonuzovoru.pdf
    • http://ez-surveying.com/htdocs/cljr/data/files/wikenakepemap.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613771ad07494---zidedali.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/57hoi6kbf78fbfs1pvu74flvm7/1094171003.pdf
    • http://makinsushi.com/uploads/files/wikoridosotetokolimobe.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=communicative+english+semester+2+guide+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_off0000d240.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD240 16792 bytes
font_01_sfnt_off0000ea52.bin
21d6f2ee5420207d0ea11a2b75e19e18335da55349c8934b28fea6135c3b87b4
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA52 17596 bytes
font_02_sfnt_off00011799.bin
0ccf5719a41dd042d91069be0cb28899359d318227d3cfc82625fa7fafe5072c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11799 11384 bytes