Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4dfe1203444fb19…

MALICIOUS

PDF

82.3 KB Created: 2021-07-01 23:33:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 671d10099e72594e1a7a86882e65215d SHA-1: ff688a783d8059d53e12020ac10a082ce6f7f1e4 SHA-256: b4dfe1203444fb195dc424bbd5e6c0818fdf4449827964d04268649153ab664a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous other PDF files hosted on various domains, some of which appear to be compromised or disposable. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure suggests the document's primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://sun-eko.eu/files/file/88731774626.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c6967330c4c---giloriwirepi.pdf
    • https://baoholaodong24.com/userfiles/file/xagopipaputofesizixogivi.pdf
    • http://starrsgazette.com/admin/images/file/20364175733.pdf
    • https://thuaphatlaihanoi.net/uploads/files/gakomipisamerexexok.pdf
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/d7fa466cb4942dc6ffe3104c73eed787/42124624020.pdf
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/8n657mpsnt96il0sf7nhqou653/56966511211.pdf
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/haoafnn56ps75ietpbkvpiallq/34955489402.pdf
    • https://sealordhotels.com/ckfinder/userfiles/files/57320734375.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/91f9881d43e54a3dcc382b1ea3857e60/bomixixulirirebuji.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b4127069d---63724448800.pdf
    • http://myucmas.com/userfiles/file/281257131.pdf
    • https://geneticapanama.com/userfiles/file/89082935125.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/44eb7028238175ea744cfdc674d576c9/vuvinegapuji.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/hvdoe6pobec6882fk0raojfmuq/83044211597.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ab54436070a---74526081830.pdf
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/ildaqgu9k9kapcpvff8ik6gvfn/84807600104.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/ru6g73d67rggssie9mi38mqtr6/wabixumigojimanadositegu.pdf
    • https://mt-creativestudio.com/ckfinder/userfiles/files/bawivesevovenas.pdf
    • https://unibel.pl/pliki/upload/file/famasutesove.pdf
    • http://amtutoring.com/clients/865321/File/jujolabelitukawomife.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=ssc+je+mechanical+solved+paper+book+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_off0000db59.bin
1ef21f99d3fb32b7244e8e94dffd4c0562790bb88d6680eec6ca6ea93ccf495f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB59 17876 bytes
font_01_sfnt_off00010a0b.bin
42aad5db891f272bc360e20a92ce2039e1e4cc7385c1feb20b7e3b331f4b538c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A0B 11288 bytes
font_02_sfnt_off0001240f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1240F 16792 bytes