Malicious PDF — malware analysis report

Static analysis result for SHA-256 e904f35e8f416e22…

MALICIOUS

PDF

82.2 KB Created: 2021-09-08 06:57:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 9d70b299eac8b4e98e1535506b580189 SHA-1: 2366aae13bddab77e53631f8958704a49e6ec1ed SHA-256: e904f35e8f416e2248495ea1672f81d3ec08dfc756adf133154f8fa3b2d30cff
204 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a LOLBin command-execution lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/94ufpagvcnt5fq8594icbb1l9i/vuriwi.pdf In PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/dvbhd0cmoa5dbtjl2mgggbpmq3/gilazodi.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/b39b23b77874e578bf8846b2863769c6/71143239082.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/paxebin.pdfIn PDF document text
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/5657914fcd1ca1022fe47f2f1a31dd1a/86515417795.pdfIn PDF document text
    • https://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/17499075168.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606fad7164a0a---makovuwumisazidunutezituk.pdfIn PDF document text
    • http://erdivigado.hu/userkepek/file/fejoletiluruxitenanikafir.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/0eb7mta4cgkd8m12eef8dsi6p4/toderet.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/qmjf0lr15q3no68bkbipoml7da/bolewipobowazazuliw.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/5190d9d9132cf926770dfa76178484b6/wufomonegel.pdfIn PDF document text
    • https://foodthings.us/userfiles/file/subofa.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/1037825438.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2bf273700---babufutuj.pdfIn PDF document text
    • http://inspirationforexcellence.com/clients/66491/File/97686225791.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/benaverulagagogemusuf.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/713764df528e0b4e59c955a22ef1fe41/warawaxalebuduvazowibes.pdfIn PDF document text
    • http://charmingcurls.se/upload/file/4979393139.pdfIn PDF document text
    • http://ghalemdi.com/userfiles/file/fexuveseruk.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/6f4128ee44549bf418163850995f6066/67270735851.pdfIn macro / runtime command snippet
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d36d779f71---pazik.pdfIn PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/jawuluwegeketow.pdfIn PDF document text
    • http://vector-mebel.ru/uploads/files/kusijolurasazojuxi.pdfIn PDF document text
    • http://ghalemdi.com/userIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=terapia+ortomolecular+natural+francisco+antunes+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD878 10844 bytes
SHA-256: 72dc68eb465262ba82f82e8e0f3698366367fcc5af6a90f91ab682a9c6ff6d2c
font_01_sfnt_off0000f177.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF177 18948 bytes
SHA-256: 59a4d940c5aa3edd94b9e83cffa6be47b289d91abc21b4b861819ec71140ac8d
font_02_sfnt_off0001228c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1