Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f1660d58573bffc…

MALICIOUS

PDF

83.0 KB Created: 2021-09-05 10:36:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f6d39255a4a4b5c336c90e2cf4071301 SHA-1: f28d73c06d91671167c19fe3c2ebed6f871ad36b SHA-256: 3f1660d58573bffcb59a6201837ce6994dc078cd1c22cc87213455e150e4e42f
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. ClamAV and ML classifiers strongly indicate maliciousness, with the primary technique likely being Spearphishing Attachment to deliver this link farm. No scripts were extracted, but the structure and URL analysis point to a phishing or redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/7cb30b539100b7db5da2b14bc9b0402d/2997446620.pdf In PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609064764b49f---39594085775.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607d14ab9f4d3---69179511701.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/210605001431593057lhg5jk.pdfIn PDF document text
    • http://netmode.net/app/webroot/uploads/files/tokigovasosepajamif.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/36658069071.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/39414241956.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/64064265289.pdfIn PDF document text
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/38111293097.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ffeacf37235---tedinofobaravuzi.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/vijatibelavomebebanud.pdfIn PDF document text
    • http://amexeuro.com/an3_Uploads/file/3421167366.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/63be6fefba585ffb57349a5ee9b18456/39611464326.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16070ce9f3cd02---wawuzumuxosisogotib.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160975d85b9cc3---kurofufigugepufigexuk.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/f64tntd6d2mks9o47ej8h5s3kr/27569342685.pdfIn PDF document text
    • http://fuga-hotel.com/CKEdit/upload/files/65905165582.pdfIn PDF document text
    • https://matskaren.se/anvandarbilder/203/files/44813967064.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/1957ee232dfae60a764cdbef204e35bf/zebutatojowibapax.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097203065abe---gusolugososabamekitovu.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/kosebatelemenaxo.pdfIn PDF document text
    • http://stroi-sistema.ru/img/89001923060.pdfIn PDF document text
    • http://carlaschroyen.com/content_docs/wavabaz.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/69629625546.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f21893c085---degerutovose.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=helical+piles+design+manualPDF 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_off0000de04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE04 10628 bytes
SHA-256: 72bcfd56a60851d2c1f1710c1a0d08215875784b81671435fe4616aaccef892a
font_01_sfnt_off0000f5fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5FE 17852 bytes
SHA-256: 2899b8a21001b742b520dd6d023c82c20593db358b39174fec2e85c16fa265fd
font_02_sfnt_off0001248c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1