Malicious PDF — malware analysis report

Static analysis result for SHA-256 9901c88541d092f7…

MALICIOUS

PDF

87.6 KB Created: 2021-07-22 22:33:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 9a87183bc3080e53fe4ad0c549c50dbf SHA-1: 6e12e5f6cd1bc761f56875c143a1b15f774e583c SHA-256: 9901c88541d092f716f06073ea6c8f45a279f7de1d9d72dfa99a317b8e8edd4f
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated and appears to contain embedded URLs, further supporting the link farm and phishing pretext.

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 http://qa-whg.net/upload/files/figaveduxur.pdf In PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/cjhdg5933771oe5tvlor2fctl0/67663529847.pdfIn PDF document text
    • http://htwy.com/upload/file/zedazaja.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b7149fe97---75776568790.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/biwetexesowaripojaxu.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/01c899686321dfd5a6bfa5fd5fc8961d/jadafixarokuluburabo.pdfIn PDF document text
    • http://www.bash.cl/media/file/gapozelaxitono.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160925777c2fb8---85366203905.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c14578bfab---52679140770.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/46352451095.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/4557483720.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/davilegifelorewad.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/bevelesalutozewitovuzote.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/oug444162r895bt3c7jac3ejq5/zoxabezaziti.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/64814550050.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/fa7ee851a545197a5055e3bc9aa9bb89/selumewatef.pdfIn PDF document text
    • http://yogathoitrang.com/quangbasanpham/app/webroot/upload/image/files/62979478196.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160987588948a0---jezokapemo.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/cprgc67ufucm31orcmgqgao6n7/9083257306.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/revidizawejiwumaxugol.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/kt3tnbde803ropctggrjnqkqol/jovoma.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/7474c9e82f90ada19ffedd3fc032edfd/lowof.pdfIn PDF document text
    • https://roweryelectra.pl/app/webroot/uploads/file/16257224161704.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/cb73h04b4tv1vg27ncbsuo8v6v/11171358186.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609423272de53---85998091065.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=german+volume+training+with+resistance+bandsPDF 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_off0000f04f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04F 11248 bytes
SHA-256: cde805f971258f234a046a5dc65797711df84c3db7ae9a3c2459d546522e6def
font_01_sfnt_off00010a5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12270 16792 bytes
SHA-256: 4f38fbef79cb856d3c5591f81a839d698f4d7559cfc6afb53ba86773fce2b8fe