Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5108eaf0329ced3…

MALICIOUS

PDF

79.9 KB Created: 2021-08-12 19:54:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0a4da7e854aab397c78ce756d0ab8ccc SHA-1: 19544526f3956469a9ece1e3e2dd850c993a81db SHA-256: a5108eaf0329ced3d2f8016f3d65b3252384828a398517d768ce6f8661925116
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://amuseonline.com/absite/userfiles/file/27359551007.pdf In PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/arirhpe5rl8pts4kt9fmc6dsl2/burugenizawanipopavuvo.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/44821976867.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/kuwinomasamul.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/87600755348.pdfIn PDF document text
    • http://deccanquest.com/konadnew/userfiles/file/27549631656.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608442cc99dd7---88215731528.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607757067fcd2---42728079353.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16070fcbf90552---raluxepogikugujevizime.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/zosinotem.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/b0a19591c7b7f1de0886bc44ba3c6cef/torozerasawadarok.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8dcd366f0---wuxanorute.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/dsjv0tg02dreir4u8d8t97rg7v/gogitotuwovodipibugiw.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1263a1ae67---90004017008.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/nekin.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/98f7af3e9a9dfd66a8a1f35916a38372/5804576868.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/dab92ce2e4664d0c83c20f25aaaf60f3/tuwanowizu.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c01555d0aa---bagezojuwilozigowemu.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/55641214113.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160af9e00b526c---diwazonipawuzif.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f35af6f01c---guxugezadilivon.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/57775397634.pdfIn PDF document text
    • http://euroteam.vn/ckfinder/userfiles//files/zubinirobopuvojiwof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=how+to+use+whirlpool+duet+steam+washerPDF 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_off0000d45c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD45C 17096 bytes
SHA-256: d809c7faf3e135693d31e9784e6404bd6c1434d7a8a4f84f4b2f645b22e5e086
font_01_sfnt_off00010018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10018 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001182f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1182F 10728 bytes
SHA-256: 57d67c1b160c5ca8017dd589af9069078b5211008dc6f040a72da704dfd7549d