Malicious PDF — malware analysis report

Static analysis result for SHA-256 a557c10e33ce4e05…

MALICIOUS

PDF

85.0 KB Created: 2021-09-07 18:19:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a0beb287bea135c7adf15cfb00b80999 SHA-1: 65d6fb518f5e86eeb23e9912b609ec4c000dc858 SHA-256: a557c10e33ce4e05eed298273b8fd1e6a6f34b4f04c5db7d4ac057e6e5759e99
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites and disposable hosting, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, and the document body was unreadable, but the heuristic findings strongly indicate a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/17ff3c973e36f08c8b5bfa6785a5f64a/rutogaponim.pdf In PDF document text
    • https://m-isc.com/userfiles/file/mebisuwapis.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160b802a69025d---59832114647.pdfIn PDF document text
    • https://fertilizergranulatorprice.com/d/files/dijiv.pdfIn PDF document text
    • https://burgas-remonti.com/userfiles/file/66859952533.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607167f2607bb---74019224543.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/n0hd0i3a51n9n33g28s92qtin1/wepogoraxakuzali.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/19377863198.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f9246087c---7481761859.pdfIn PDF document text
    • http://lingeriedediva.com/UploadFile/file/2021082505274373499.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/kuxedomagaxomebug.pdfIn PDF document text
    • http://skene.es/userfiles/file/61407178194.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c4173aa7c91---46228189182.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/vabunu.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021071303202773499.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/631ec382462916ad86c1f4022341804c/70696429571.pdfIn PDF document text
    • http://alarmy-kamery24.pl/userfiles/file/vijogusix.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/dizejuduxof.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/98dd9181d11be281f315ea72d2671ad2/41924940138.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c455956b3---dojuzunelurezakovav.pdfIn PDF document text
    • https://girl0229960192.com/upload/users/files/92213180837.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/0a5434e9b5498d173d4de98908c343b5/50076402370.pdfIn PDF document text
    • http://tverzhilservis.ru/foktver.ru/ckfinder/userfiles/files/mulaxileburip.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc7088098f---keravuruwewajenetor.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606d637149b61---ximixekex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=otis+506+nce+escalator+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_off0000e7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A1 10940 bytes
SHA-256: d3941be36bc6fb2a793c55de9ac0e7b946301910f2836cf9e3cfbca4047b44d5
font_01_sfnt_off00010102.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10102 17448 bytes
SHA-256: 3f319635c2d84cd1c2694d7cc12f2d8ea87311788034b2cedff3d1901557a4c5
font_02_sfnt_off00012e96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1