Malicious PDF — malware analysis report

Static analysis result for SHA-256 f335a7833c9ca0c3…

MALICIOUS

PDF

81.0 KB Created: 2021-09-10 11:57:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3c1bec18291d18dcbd964e193054cffc SHA-1: 09cfb08eb67c2b2bed4a6dddd0ab6a1101ed3dc2 SHA-256: f335a7833c9ca0c3fb543ceb0f675fddb1e912c50a336b0871d591c7d03d6c51
164 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress uploads and other disposable hosting, suggesting an attempt to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://garagehayashi.com/js/upload/files/61300116498.pdf In PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/ui1t1bq3cjopmmqcek1hu3ho7n/93176305453.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613052a092937---gipekidapimifenipakikaj.pdfIn PDF document text
    • http://lngpetro.com/userfiles/file/9936690987.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae3ea131f6---delipodozutevofamavagit.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109101208324900.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/3sl2pm9kao7ino1jjblvsq04g1/sofinanakiroze.pdfIn PDF document text
    • http://tapestry.cz/images/file/files/wodajukurupitisozubix.pdfIn PDF document text
    • http://tms-technology.com/ckfinder/userfiles/files/71876623746.pdfIn PDF document text
    • http://nadafashionbelt.com/Uploads/file/tedugetasogoj.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/l5dobi484mjph4cecgu6qmed5q/12839410782.pdfIn PDF document text
    • http://mamaskitchenorder.com/uploads/files/91584265488.pdfIn PDF document text
    • http://poliinc.com/upload/files/fubefugenolefeloke.pdfIn PDF document text
    • http://guss-ex.de/uploads/fck/file/sitejawuramored.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/56653414760.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/xalobaxu.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/lodakorajibuguwaxuxaren.pdfIn PDF document text
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/desidunokujiwamatep.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/3985061543.pdfIn PDF document text
    • https://tadimtursu.com/image/files/donijonegipazalegujusilej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=way2sms+free+sms+internationalPDF 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_off0000d97a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD97A 10604 bytes
SHA-256: b7ae73e1d8feec8e53e31a689229538addd502f7c61d7cd198c651651e65005b
font_01_sfnt_off0000f1c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C5 17104 bytes
SHA-256: 8bead4b811e39c18d2c2d0d5bcd300265bd27df13d380fece6af2f19e26e5ae0
font_02_sfnt_off00011e3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1