Malicious PDF — malware analysis report

Static analysis result for SHA-256 b772e60f656da926…

MALICIOUS

PDF

83.9 KB Created: 2021-09-04 19:15:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: dad0c36a13e1fdb16161b69084d30fed SHA-1: a5647e153b8904b112d88acb222b98a9d48ec521 SHA-256: b772e60f656da926a826498da7441e2fac5b86b5567615bbb3e1609d5284033f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://synerhu.ru/uplcv?utm_term=teaching+styles+book+pdf PDF link annotation
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c5826b6390b---24972367571.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/8ce0c4d60b396d6a88306566b363951c/4314041918.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/koxat.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160c7372dbcc4c---kojabikixapunememe.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/fujivekobamulutafoz.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/n3gjimgvvqpmf1qhovtbgiijuo/81196892409.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/suvijur.pdfIn PDF document text
    • http://classtool.info/upload/files/61018577352.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/95a074f4610728bd9039108036854870/16334520235.pdfIn PDF document text
    • http://barcelonasixtytwo.com/userfiles/file/rumimabanititi.pdfIn PDF document text
    • https://dancleland.com/img/upload/file/61432795082.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/d86ff424634babd54b72bb0382f73f2a/35622414502.pdfIn PDF document text
    • http://iltorg.ru/upload/file/lawiwa.pdfIn PDF document text
    • http://jingchengs.com/jingchengs/ckfinder/files/20210727010947.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/74438785085.pdfIn PDF document text
    • http://xn--b1adcbbai1bezln.xn--p1ai/content/File/80770265720.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/rivojabiw.pdfIn PDF document text
    • http://klinok-saintp.ru/files/gixejifovowikada.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/zojosopujagupiwusa.pdfIn PDF document text
    • http://ubest.ru/images/file/zizupevafet.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/wigurekezemibitufimalov.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae82756579f---dazunire.pdfIn PDF document text
    • 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_off0000e457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE457 17052 bytes
SHA-256: 231deda45a56853da453fc869c45531caa0e4831a3ac25c3626c42b2edd361a1
font_01_sfnt_off0001107f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107F 11108 bytes
SHA-256: 754ed0be41c9a24c4398fbf908b6bce0e7edfca4bc00dcd753374eb3baa871df
font_02_sfnt_off000129f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1