Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb798aa2c14a8113…

MALICIOUS

PDF

95.6 KB Created: 2021-07-01 13:54:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b6c4aeb0c394692cc9ab2cebcc6436b SHA-1: 38945ef6e4575e1904df567d93da1e457f4ad42e SHA-256: cb798aa2c14a8113187c5083e10768fd4eb0caf3aad454f9fc9bfe42f5a87926
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a pattern of using these sites to host or link to malicious content, likely for phishing or malware distribution. No scripts were extracted, but the structure suggests exploitation of PDF vulnerabilities to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9786

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://irlanc.ru/uplcv?utm_term=scientific+words+that+start+with+y
    • https://ebooksweb.net/files/file/nobifokiw.pdf
    • http://caf-ljubljana.si/docs/kuzumi.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/d12fafb4d336dcc1729252993e848270/89101962615.pdf
    • http://yourtruck.be/upload/ckeditor/file/betozoximewuronibukelewib.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16096e5db16837---78437422137.pdf
    • https://etonbio.com/newsLetters/images/file/guzarurofanawitive.pdf
    • http://albino-pitti.com/pub_img/file/8555406097.pdf
    • https://citronixdeflection.com/nbloom/fckuploads/file/21386714402.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b37dae2f666---99979540265.pdf
    • http://begemot-rus.com/uploadfiles/file/2021051400174773499.pdf
    • http://golden-candies.ru/webroot/files/files/pajaj.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3fcc94be06---90469817563.pdf
    • http://apluskleaning.com/admin/images/file/21874813449.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608829b0235ef---13685647715.pdf
    • http://bowlinggreenhsclassof66.com/clients/b/bd/bdf8ab256cd88a603fc2b95a051c5839/File/22932727150.pdf
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/80fd53d55e056a4a4a20a8be37414690/komejavapujoxa.pdf
    • http://bachova-terapia.sk/images/file/19497748486.pdf
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/f21d2c4fc481d7a980e581477264c61e/99509986114.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/51000930065.pdf
    • https://wemservice.com/ckfinder/userfiles/files/14960653713.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/75730b163dbc05380830be04fa9aa88c/76884249553.pdf
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/47d876cc0dfcf20d8ee6e86d0d9677e1/16551766523.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608135fc2d142---gazekalakapazivewujap.pdf
    • http://hoangle.vn/uploads/userfiles/file/25810395721.pdf
    • https://shoppingplanet.ro/ckfinder/userfiles/files/wunene.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160c8bf7436bf5---tegexubakoj.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa17.bin
4ae98fbec7d8ee2fe144403e4ffd712020c6413de04e77ab0b7bcb3c664b8172
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA17 17452 bytes
font_01_sfnt_off000127a1.bin
9f6ed0e07ff32a36df51bfe8b4f04396ddb21a75076e79bf8ea9215ffd770034
pdf-font-stream PDF embedded font (sfnt) at offset 0x127A1 10800 bytes
font_02_sfnt_off00014090.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14090 16792 bytes
font_03_sfnt_off000158a1.bin
bfc7ce51a1a9b37382af61f0075eb0cdb972126da031002d338643432d80e6e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x158A1 16252 bytes