Malicious PDF — malware analysis report

Static analysis result for SHA-256 7426b8c14db54a7c…

MALICIOUS

PDF

86.7 KB Created: 2021-06-27 23:28:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4a5cd1de9b4a06889180bd69f17e49eb SHA-1: 21f8ead489674eba1fa8cd66c41cc55d6c5839cf SHA-256: 7426b8c14db54a7c13c85748904cf3b31d57fbe240f858c14b77018dfc941a61
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by multiple heuristics and a machine learning classifier as malicious, specifically identified as a phishing trojan by ClamAV. It contains numerous links pointing to compromised CMS upload directories and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://pistant.ru/uplcv?utm_term=pulsed+shortwave+diathermy
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/e6ce577239ad2c69f279410d48b62e09/jalimefesufetu.pdf
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16081cf7057f4a---zegumisade.pdf
    • http://alibabashipping.com/userfiles/file/sokod.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094961b24e98---2045481040.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606f24d37f56c---87351128519.pdf
    • http://kleinschaden.expert/userfiles/file/ruvewomepavometabu.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/paqocsvu6249jsrqfsvm13e0eo/61617575161.pdf
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16080ca39572b4---kejovekumajo.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076cb585e1fa---wadukufepolutufeg.pdf
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/212f164ce00024526ad7bba24c149384/wawow.pdf
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/2de29488fa55a1c8fb669f50865ff536/43369014792.pdf
    • http://casinodanmarkjackpot.dk/userfiles/file/rupexuxesozezevowaz.pdf
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606c914a5d847---80928023045.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609c24e8d00eb---5844157100.pdf
    • https://bloomeng.com/uploads/fivizejikop.pdf
    • http://thevisionkharj.com/userfiles/files/soriz.pdf
    • http://szentimresiklos.hu/upload/file/73027658131.pdf
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/395ea1e9e78421f543047d6fd6f8c913/91531827532.pdf
    • http://pastoret.it/userfiles/files/xipumegasoxujivitatidu.pdf
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077c5f597686---lejituxobisogefu.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c1d53987070---51929399078.pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce218a3e02---1747180974.pdf
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/43d9b94db0c1f501f0025299e51f955b/38242569668.pdf
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0869653372---31633124245.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_off0000ed73.bin
db904a447d9f96f1cb1de2a2455f19cfc5f20b323859a4e789ce8bd8c9a55c3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xED73 17868 bytes
font_01_sfnt_off00011c6c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6C 16792 bytes
font_02_sfnt_off00013483.bin
e4a99b3298bece839205f78fbb8159391a054b2128933ec7bde562166125efa5
pdf-font-stream PDF embedded font (sfnt) at offset 0x13483 10776 bytes