Malicious PDF — malware analysis report

Static analysis result for SHA-256 36991dcc7a03a124…

MALICIOUS

PDF

88.1 KB Created: 2021-07-23 02:42:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 89097f7bba147d33f93876e05c6d4e6b SHA-1: 940261f6db0a7179e89f5a36e8848d7efda30866 SHA-256: 36991dcc7a03a1240478dbe856e0f86943db40443c23264ce282060745c35b4d
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress upload directories, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document's structure and embedded links are consistent with a tactic to lure users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2175f6b9dc---jugijusudepazuweto.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079e7adbd732---luveturur.pdf
    • http://dajuicebarus.com/uploads/files/zugikifenej.pdf
    • http://bezpiecznamlodosc.org/files/file/13071271976.pdf
    • https://cristalensi.com/public/File/modabotuwudifawudod.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f95f1bc7ab---81633563035.pdf
    • https://bbmint.com/userfiles/file/wukijikas.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/8fe8913e9041937712043aade5c76aa6/tabawam.pdf
    • http://cdkkck.com/uploadfile/file/20210620005549.pdf
    • http://wrhs1967.org/clients/6/61/617565fc8afb9cc6d18abf932d248b7a/File/17662092489.pdf
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/bepn8brm22u98bt2bvto00fai9/kerasavoxubetiv.pdf
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/rbqrr20eo00sgmdqhc1d6nbiqt/ditimupa.pdf
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/qpe375ta2n7h6956cr4d1k6h9u/tidipipavukuwawixe.pdf
    • http://anhuizhkj.com/upload_fck/file/2021-4-30/20210430185435990896.pdf
    • http://kuhomania.ru/ckfinder/userfiles/files/vorixe.pdf
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/timudetuvupibezo.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfdadc4d0b---29323887591.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/b7248fca0ae5f401d3d850a0d7b015a4/12396329423.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609164276307e---10369416364.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/a3bd7cb20c634b9a6bb6a5f9fb30e516/lixak.pdf
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/0462c7725132ae74a334d022cb0c5760/juvamipivenasotawemen.pdf
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160d9169ddec56---milorovewikes.pdf
    • http://falerisztika.hu/tmp/93489132664.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=nor+gate+is+equal+to
    • 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_off0000f587.bin
f84ce3ed2ddcc796fba3c64a75c9dc7b4c50a9ff53a66261f44e3d27e4664b44
pdf-font-stream PDF embedded font (sfnt) at offset 0xF587 17200 bytes
font_01_sfnt_off000122a7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x122A7 16792 bytes
font_02_sfnt_off00013abe.bin
ba812dc8c310e263a5d3ec2da4458736dee34a3c8d35831679c2c88eb63d93c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13ABE 10404 bytes