Malicious PDF — malware analysis report

Static analysis result for SHA-256 043b1c914a1f5735…

MALICIOUS

PDF

84.5 KB Created: 2021-07-05 07:08:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91b9b4cba14132150172ed20e34d9a4d SHA-1: 86485dc9d888b0eb63e6b480b3eeb1cac7e14db0 SHA-256: 043b1c914a1f5735ccba45a264b9a86460fbcd6ece8f94190d9bab4af7f2ada4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing campaigns that leverage spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=tips+to+write+an+informal+letter
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/na8o49ah7vrntal4frpefou4f0/79917219746.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f46e09262f---28637275654.pdf
    • https://medicentrumnz.eu/medicentrum/files/file/3769382647.pdf
    • https://hchoanglong.vn/userfiles/file/lakiwuluvewikilu.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0400943d17---safogurakib.pdf
    • http://riversedgefm.com/files/file/sujifipewajetedipufon.pdf
    • http://sns-russia.ru/userfiles/file/93095472806.pdf
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/xilezibetuzajoteguxaj.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bc41f85592f---pizanipiduzux.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bc1578be251---25978630405.pdf
    • http://carlaschroyen.com/content_docs/gotosonag.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/69f397d0f509e8c1c4a2dd2192c97eab/kixasoselikukezizazewezok.pdf
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/ihv5r42s6a96cut4or954cn2jr/78905855148.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b39a7d95919---72420446542.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607787b329a80---tapedalenodikukinari.pdf
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/195174921360a6eb24220c8.pdf
    • https://rabudiagnostic.com/userfiles/files/87128590157.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/a0918cbc301085ba6c5a3035c79d8867/wiwirutibasurawakis.pdf
    • https://argumentua.com/i/file/16252962189.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5467df34a---28063021683.pdf
    • http://bularz-auto.pl/images/userfiles/file/26500363639.pdf
    • https://groupunsur1.com/contents//files/temelaruto.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b321df620---pafemejadakubuduk.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_off0000e7ac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7AC 16792 bytes
font_01_sfnt_off0000ffbe.bin
699f15b641dbcc52aaecb9d5dbaac6c278d90d610140785e1507be68a9aca1e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBE 17128 bytes
font_02_sfnt_off00012c6f.bin
4695827e7b38b5b826ec68bdd5a128a8df80626a7dc8a7da55d55318465ed474
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C6F 10568 bytes