Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb091df0a8509de8…

MALICIOUS

PDF

84.8 KB Created: 2021-09-20 12:36:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3b46d8c4b12f2e7e1aa96660e59061c3 SHA-1: 3616723f927a33e5edefa11ae281b33f8f814943 SHA-256: bb091df0a8509de849b3af5348eb34c4a95d9e3ba69e757f6dd75c9dba2e970f
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 WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of external URIs and link farms on compromised CMS uploads points towards a tactic of leveraging potentially untrusted hosting for malicious redirects.

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://drafthe.ru/uplcv?utm_term=schrittz%C3%A4hler+app+android+ohne+gps PDF link annotation
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614119536faed---93965233710.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/91040945978.pdfIn PDF document text
    • http://kahounova.cz/userfiles/file/xivawuzaw.pdfIn PDF document text
    • http://triple-a.co.th/ckfinder/userfiles/files/binevikudominadaw.pdfIn PDF document text
    • http://farmina.ru/uploads/files/87978577679.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/93189384232.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/kenekunuxuniga.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/kejunupajeboxufulovadewex.pdfIn PDF document text
    • http://mutamobilya.com/images_upload/files/96198791689.pdfIn PDF document text
    • https://firsatoyun.com/calisma2/files/uploads/jepewili.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f384967e8f---19123994848.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/vexuduli.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147acffdd211---kujitazoneludojejat.pdfIn PDF document text
    • http://nissanzorba.ro/ckeditor/ckfinder/userfiles/files/dolebosifegasudi.pdfIn PDF document text
    • https://efficientinfocomm.com/ckfinder/userfiles/files/kikijijekufulubupavek.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/ninezugatonet.pdfIn PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/wamere.pdfIn PDF document text
    • http://www.grupoaccs.net/ckfinder/userfiles/files/dopumox.pdfIn PDF document text
    • https://weilmclainboiler.ca/fck_upload/file/59282705185.pdfIn PDF document text
    • https://towa-aaa.jp/userfiles/file/40781893943.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/rubanidatizijub.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/zipumitegofamoxazulalew.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394c8a1654b---sogunojitopoz.pdfIn PDF document text
    • http://www.andreapondika.cz/file/sosamapolunitenu.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_off0000e362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE362 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB79 11184 bytes
SHA-256: 483c79961c3226a6ae15200e75fb4faaeaae70891ebe1ddede06151cb80d2895
font_02_sfnt_off000114e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E0 18192 bytes
SHA-256: f3ba3dcd10baa5b429c22c3f5c8b2d604342850d0c45817321a3582013c79ebe