Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbf1b30c812acd20…

MALICIOUS

PDF

88.1 KB Created: 2021-07-01 15:45:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 85e1cf34e928f40d38108f29acffeec9 SHA-1: 6b57ea8c63b055fab8ef8ee9faa3acfee41500ed SHA-256: dbf1b30c812acd20c63ae522099a7df0affe01e9add4bcb174b91fa3dd626f09
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many hosted on compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving exploitation of PDF vulnerabilities to redirect users to malicious content or download further payloads. The document body is unreadable, but the heuristics point to a link farm strategy, possibly to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://crysiq.ru/uplcv?utm_term=principles+of+physics+10th+edition+halliday+solution+manual+pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082683965823---76638081534.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1b38eecd1f---jabonaxojof.pdf
    • http://animationcoach.com/userfiles/file/43953893398.pdf
    • http://goref.ru/files/file/miravanofaw.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-5-2/20210502070253824875.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/0fe384bad556583049480eaf85d8a179/biwigunufajuzi.pdf
    • http://gramercy-grand.ru/files/file/18615357336.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160820aacbf579---90300014229.pdf
    • http://tsutae-f.com/js/upload/files/95254080939.pdf
    • https://schmitz.cz/res/file/27718294209.pdf
    • http://cuatro-pr.org/sites/default/files/file/24343287580.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f8fc8a07ea---24366313737.pdf
    • https://comiconfezioni.it/file/26076458072.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/8e1a4397119b2c921d89d194b69214c6/fobipid.pdf
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/19278db43001c11ac469994663dbf0d5/bosajudupiwexifopasadumap.pdf
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0809750c2---jujokasab.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/52627363834.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b6019488b3e---varewibasagiginanunapog.pdf
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/cf5b0265282326f2050229c335b2334c/45143156358.pdf
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/3d3b91cc64d040491bb6faa226173cac/fivipumatironofader.pdf
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/10e77ac874b5c8662b80164a606aa87b/94142719147.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160919593eb84e---20601233729.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/11fef09b72dc2c04fbdd7bee4450bc96/50086013506.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa06590019---rosugesuti.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fbe23e81817ea071342408905882766b/56438090933.pdf
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160adc3c3bec9d---fufoki.pdf
    • http://bharatdarshan.net/rgroup/ckfinder/userfiles/files/45743867132.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_off0000f035.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF035 16792 bytes
font_01_sfnt_off0001084c.bin
f6b2943f4ca8fe1b05c40a26a3526e80e0f5112ef8eb8b148900babda156b3c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1084C 11276 bytes
font_02_sfnt_off00012296.bin
4e000d2e0628424aad8ca8fbad4e173be1eb24a42121aea65d23096f481f22ef
pdf-font-stream PDF embedded font (sfnt) at offset 0x12296 18328 bytes