Malicious PDF — malware analysis report

Static analysis result for SHA-256 b922e23e30ddf85d…

MALICIOUS

PDF

83.6 KB Created: 2021-09-21 19:08:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2313a0ceedb7c3de59a3bd4e12993bba SHA-1: 44de4f15a8f97cc1444c026e45969833ca12683b SHA-256: b922e23e30ddf85d8fde80e5bd8bfd07cf2da981b81a3477de522ae6d3e2a0da
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript, a common technique for executing malicious code within PDFs. The presence of multiple external URIs, some pointing to potentially compromised WordPress sites, suggests an attempt to redirect users to malicious content or phishing pages. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm structure, likely to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://vietrocknet.org/app/webroot/img/files/digafunapebiriwojuga.pdf
    • http://www.thaitofu.com/image/upload/File/mapugarupevu.pdf
    • http://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/99889114690.pdf
    • http://hoangminhsaigon.vn/@dmin/js/ckfinder/userfiles/files/77185878894.pdf
    • http://saiprogetti.net/userfiles/files/zisasex.pdf
    • https://f2h63c2.ip4secure.net/upload/files/98831913310.pdf
    • http://divapharma.com/uploaded/file/61614756658.pdf
    • https://jhservice.net/imagenes/galeria/files/9202103866.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16149c9ae2ae26---43130642733.pdf
    • http://janjoling.com/public/ckfinder/userfiles/files/rufetomag.pdf
    • http://cestovni-postylka.eu/userfiles/file/46611733401.pdf
    • http://www.77ice.com/upload/files/fajugewofaxumowusezafaw.pdf
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/6tmdp86etrc430cl24979s98ig/8952496268.pdf
    • http://siripanyalamphun.com/user_img/files/kuravuxopesufef.pdf
    • http://www.premiumimport.nl/ckfinder/userfiles/files/94268721508.pdf
    • http://stl-hk.net/userfiles/morekimiko.pdf
    • https://autotronics.vn/userfiles/file/3456174185.pdf
    • http://architetturaurbanistica.it/userfiles/files/64402257634.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134318c2ae3d---boxipawosalabofora.pdf
    • http://thingsantiquesla.com/userfiles/files/vevakiruxunaxugabaradaro.pdf
    • http://mayepnuocmia.vn/data/ckfinder/files/donedo.pdf
    • http://cz-synergy.cz/data/file/35325565475.pdf
    • http://krevue.cz/UserFiles/File/jexizivusaf.pdf
    • http://highlevel.pl/userfiles/file/sewagigitesawepelumiv.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=root+android+10+xiaomi
    • 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_off0000ddd5.bin
b9bf8379defc89138dcf27a188a40c0816eff3a0b99c241433fff7be4740a8ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDD5 10384 bytes
font_01_sfnt_off0000f553.bin
5eebf70b0f99af32100702f039e8f815aae18077bd55730967c5e6549bd2e1fb
pdf-font-stream PDF embedded font (sfnt) at offset 0xF553 20092 bytes
font_02_sfnt_off000128cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x128CF 16792 bytes