Malicious PDF — malware analysis report

Static analysis result for SHA-256 d93b9eb257a5c64b…

MALICIOUS

PDF

84.8 KB Created: 2021-09-15 19:44:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6c768e3b05cb3fdeab5cfe71142c519e SHA-1: bcb466ebc09c03833ca1329d107c1987b794fb5b SHA-256: d93b9eb257a5c64bdfb16cddee6ce7f7b1e529d62607a78ee6d737d1199ce80f
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, but the presence of external URIs and link farm heuristics strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://kythuatviet.vn/uploads/userfiles/file/tilifawexoguwunapazid.pdf In PDF document text
    • http://dulichtantai.com/files/uploaded/files/51335690506.pdfIn PDF document text
    • http://konikanarrowfab.com/ckfinder/userfiles/files/35953718721.pdfIn PDF document text
    • http://mfahk.com/upload/files/36576544730.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/midaromosolum.pdfIn PDF document text
    • https://buka.ru/sadm_files/fatifujetudafivomexumijam.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/7rlhe1c5iasu25334nef3620hi/37872444546.pdfIn PDF document text
    • https://gilboamedia.com/userfiles/file/mexasimajulanezekinobi.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd03803494---gowakodesisuputovuzifanoj.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/suzabizafelapizixesud.pdfIn PDF document text
    • https://oolong-dining-co.com/webroot/editor-uploads/files/larotazewonodubikunugo.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/77976414833.pdfIn PDF document text
    • https://vhcvietnam.vn/ckeditor/images/files/voxaxijosafisabuxedusiwuw.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/89412777815.pdfIn PDF document text
    • https://angkaganjil.com/contents/files/59524944496.pdfIn PDF document text
    • http://www.agenbenangbandung.net/file/36301078298.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/59749091223.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/lui4473eh2cud6543oiflm8uk2/89945176027.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/24963828533.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109151625263360.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109132209311258.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/xexugurexu.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/d557e1547172ca15c4b1fc1d7818ebbe/dugezizozejero.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/lutubu.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/86dcbacf2b586ecc06ef655f52b1f050/zovopebefo.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/b3kh2bodf1pcbd0edbt7f8laq4/gixakelijajinepisaganav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+play+games+with+gamepad+on+androidPDF 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_off0000e5c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C9 11028 bytes
SHA-256: 278a731d75ac73eab6b7861cfc4fd56467545c8f4600ca57312a8aeb8f5f41ea
font_01_sfnt_off0000ff13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF13 17876 bytes
SHA-256: d2f35b4fd73109c6fe1dcb0a330c6630d3b70bec16c4df0354e94b66be8c94b2
font_02_sfnt_off00012d19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D19 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1