Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a13b8eb66659a5…

MALICIOUS

PDF

100.1 KB Created: 2021-06-26 07:02:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a4c384d3b6cee0c911d23915c43c3e40 SHA-1: 75e0a1fd055aa208a4b8fe73e72f3d7102091aba SHA-256: a3a13b8eb66659a5086674aebee8c542b44ad6282f3f6a47d9a5a47fdcc85d68
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised CMS platforms, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/0nh5rkuvc8t29fnk389ur9gb8j/nuvuwuzegepaxejapuwora.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/74161617bd29e7f534e8ba25dc0db3e6/zizolafuvovoru.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/b6ec64462515b01585b7cb23baed2c73/61272049790.pdf
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae227792a7d---44136134923.pdf
    • https://aashianarealty.com/file/lekolesovunufabesilitugol.pdf
    • http://gyobel.it/public/file/17127959072.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086124474695---gipikifovasowegi.pdf
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/06243ba77582bd825c37763d31a181b6/5415666524.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b989bfc661a---rokigaribetofuvo.pdf
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/3b7b13a6adee563c8406a2523bc25e6f/12201309197.pdf
    • https://oxi-dental.ro/imagini_ws/18174345268.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083c0405ab5b---82183505505.pdf
    • https://paperland.bg/uploads/file/tovopipadefamobibusasoza.pdf
    • http://sity-luxe.ru/userfiles/file/33244793323.pdf
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/e6c66eab68a03bbfb607cedd3f8d7c6b/konepigizututibewa.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084691c3fc39---gerod.pdf
    • http://irinaburmistrova.ru/files/lazojekusurimamin.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b487b1e2e---10542361236.pdf
    • http://www.tomasjelinek.com/img/pub/file/43170431919.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/d5be169b351453625f9241fbabcba6ff/55824433224.pdf
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/117fc68915358af03a63e4bd12ad7e99/42307978615.pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/3nnd6epoj75q5f3ca2fla9b8p0/jevikoxifofivovefir.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=how+is+artificial+selection+different+than+natural+selection
    • 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_off000123d5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123D5 16792 bytes
font_01_sfnt_off00013bec.bin
62ea2bb0d52069b65de3a176db4052215a90ea5a1a88455d970c4ce171fe9522
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BEC 10752 bytes
font_02_sfnt_off0001549a.bin
0a8f55d9c02c065f3158db2c05ff522c415e424842e085f95ccbb9bee3a21198
pdf-font-stream PDF embedded font (sfnt) at offset 0x1549A 18092 bytes