Malicious PDF — malware analysis report

Static analysis result for SHA-256 c748db1bf542634c…

MALICIOUS

PDF

85.7 KB Created: 2021-07-01 19:22:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 551712398ab46229ba1b9d2f86ffd97f SHA-1: ef847cd81f759718b5234f1680a6c1104077e0cb SHA-256: c748db1bf542634ce8fd97046ff9d96cb9eadb52ccef4c415e3e38a0a92674ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting and link farms, suggesting an attempt to manipulate search results or distribute malicious content. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing or malware delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/hsek0unjvm93fp8ecm6vc529kb/jejoregadifebej.pdf
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/zezixa.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/cdb16105bbabc59e280c41a8247152a8/28701324635.pdf
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/dbjsnclh0ufm2a8jrlsjkoeef6/razisefuzuluzavizedataz.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf8964a233---zezuzusan.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a0cf456d41a---musovinakutotilo.pdf
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b43990d78e8---kujozutexeposugirujo.pdf
    • http://anhuizhkj.com/upload_fck/file/2021-4-30/20210430021958516131.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/pagidifuribuzigajibonumir.pdf
    • https://accuratesearch.com/userfiles/file/21882371541.pdf
    • https://stef-nancy.fr/upload/document/dufisodamurumu.pdf
    • http://skupka23.ru/upload/m/38253424721.pdf
    • https://zabulgaria.org/userfiles/file/43836730673.pdf
    • http://eastcoastbiker.de/sites/default/files/file/jovexupejabil.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/b844c30d6e608d4f5d4d2fbd48d2efec/51941992203.pdf
    • http://ampletrekking.com/userfiles/file/wotonojifozusinakixen.pdf
    • http://atthaya.com/file_media/file_image/file/88079379074.pdf
    • https://chiuman-hk.com/images/file/lenajavuxaxivulap.pdf
    • https://netshopnepal.com/userfiles/file/65047837259.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/1c96cd820b5fe75b2b33f8930d9dc53b/1252933675.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-5-3/20210503094822969886.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160afc5b6356b4---fomomizeredivuwudu.pdf
    • http://lynhuagiasi.com/Images_upload/files/43470671588.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a085072fd7---9056580398.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16095f71715551---78842013250.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc3402791b8---nuwofakalisub.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=what+colors+to+mix+to+make+dark+purple
    • 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_off0000ecb6.bin
a9bdf2d46644c0ff5ae4d069fe1fc293d3ea01e5247fe50e5d5567b6a9e88116
pdf-font-stream PDF embedded font (sfnt) at offset 0xECB6 16784 bytes
font_01_sfnt_off000117a9.bin
4034f06a02c708519f221a56dee5598e91e1ad04b6a281d57d3602393a4d35e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x117A9 10960 bytes
font_02_sfnt_off00013124.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13124 16792 bytes