Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b51872c1023c6e…

MALICIOUS

PDF

74.2 KB Created: 2021-09-03 04:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 97f9121ec29488894c6d05ef305afb2c SHA-1: 33bd0a5c5f22de9c71fd0b665d5e372192d2d2a2 SHA-256: f4b51872c1023c6e1d81e95bc0268caca6235dc9f8430582656c6bccdec5b9c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF being a link farm, directing users to compromised WordPress sites and other suspicious domains. The presence of external URIs and link farms suggests an attempt to redirect users to phishing or malware-hosting sites, likely as part of a spearphishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

Heuristics 6

  • 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.
  • 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://crewmak.ru/uplcv?utm_term=unearthed+arcana+pdf+1st+edition PDF link annotation
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd4c2006cce---7239686838.pdfIn PDF document text
    • http://dopuskvsro.ru/UserFiles/gexatoluxojuzekedosove.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083bdb329568---lefegogok.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f2b64653d3---2843083428.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2508fb2358---27567277187.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/nelidakuwe.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/77619333790.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/95771611499.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/f7aedf5b521abc9f83624c5c5f5d29a2/pewilugonisuvutizetewer.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/zebopurem.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b00a273391f---xokufujuzufiketudipefaj.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/vnql8k8dqp6rt97n95srvn390o/44269576505.pdfIn PDF document text
    • http://bertolinacare.it/file/digamafopi.pdfIn PDF document text
    • http://koyomisushi.com/uploads/files/dategoxowunaxolaweva.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/vixamakelokawopew.pdfIn PDF document text
    • https://turkihale.com/userfiles/file/65921188992.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/1d2dd2232169670849ab7268b043e6da/62176714382.pdfIn PDF document text
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/8fcc6cc2bd0f78655c35335d7845b00b/fowodixemudevuja.pdfIn PDF document text
    • https://adreshosting.com/calisma2/files/uploads/36637892220.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/c4ff6ektcno03cvrqpgpknnkvu/pekapelirifififepimuwari.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/vasunupigedoz.pdfIn PDF document text
    • http://abwmechanicsville.com/uploads/files/5241486860.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/95152784994.pdfIn PDF document text
    • http://cwesp.biz/upload/file/lagovovetavasumotegawozab.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f24607b346---tugufaruxizisexasetel.pdfIn PDF document text
    • http://tractortools.cz/ckfinder/userfiles/files/velitavozivimik.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_off0000c087.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC087 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d89e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD89E 10728 bytes
SHA-256: eabe35739be7e71df274fd96679c2cc28689befae9e67295b896a9b6968bbc58
font_02_sfnt_off0000f13d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF13D 16376 bytes
SHA-256: 84c2e519d2c8e0d18b8adf3fafcb3170858ba970159f2817db2478c64c8bb90b