Malicious PDF — malware analysis report

Static analysis result for SHA-256 8db3648a3f561fa0…

MALICIOUS

PDF

86.9 KB Created: 2021-06-28 19:51:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f3958ab0fb68b1588159a05ecf492c1 SHA-1: efb5efd387c7c7645eed9a4198ba9f8fa486d863 SHA-256: 8db3648a3f561fa0405d292f14da0d9bf3f1e6c63f0af2925dd4ec79d6c54d55
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to potentially compromised WordPress sites. The embedded JavaScript likely executes malicious code, and the link farm serves to obscure the true destination, increasing the likelihood of phishing or malware delivery. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM firings supports the attack pattern of redirecting users through a series of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://birnagarcollege.in/userfiles/file/jipeg.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0bfa3df05---xagamasutubawimimewoxe.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa81d0a2be6---79521122447.pdf
    • http://guides2alpes.fr/uploads/file/narujabumaxifebepasot.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1e2583b4d---91689125948.pdf
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160778aa2215a9---wopubuv.pdf
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/9b126ae55c1921522d3c4b27a8afd560/widavodipuxezitazefi.pdf
    • http://merwepizza.com/upload/file/39266779017.pdf
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/f7e0e20577d46fed6c7e61b064fb7248/18046048053.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088345741545---66896955196.pdf
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/26b9d82659b5ac4f015824fe0a911efe/volaxerisexugubodutixulok.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609edd183dfd0---4853646887.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd095dfe3e---45026955385.pdf
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/a73bdef127e2af6269d912eb5029a807/50172034037.pdf
    • https://minervatech.work/js/ckfinder/userfiles/files/87548931233.pdf
    • https://autosaloncenter.com/uploads/file/satewisosusaminewesi.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1606d1d90cf77c---vimumifogebi.pdf
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160987b5d7d64c---defononotonozen.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/3b9bd525e6cb2dbe309ce8f67e18d627/23752833002.pdf
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/8ct4u6ki9b2scoa9rf8c6u0maf/84002518643.pdf
    • http://nextgt.eu/uploads/file/rowoxipogugisav.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3fe1468f6---28600383221.pdf
    • https://grup-insaat.com/userfiles/file/tuxekuwelo.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6b23356a2---22945239331.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=as+mentioned+in+the+email+below
    • 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_off0000ef92.bin
51dc742a743de474e814aa7d33cf1c68c04c123015b49387e31f5b3da83508e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF92 17740 bytes
font_01_sfnt_off00011e0e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E0E 16792 bytes
font_02_sfnt_off00013625.bin
ed027008e38b16e735e2f7ab7d66474c71bca6087c32e5998ae1cdb22ab51bf1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13625 10620 bytes