Malicious PDF — malware analysis report

Static analysis result for SHA-256 9dc5f4141e95d026…

MALICIOUS

PDF

79.2 KB Created: 2021-09-09 13:43:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a64f17e638f5f832d9f1784b67083237 SHA-1: 9e0ebb8c529cb54402c67ce6d964590bf6373fee SHA-256: 9dc5f4141e95d02638dc93e7a8cc7511d2f83c2d2be227c906ef53d184e56e90
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics as a link farm, with numerous external URIs pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics suggest.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://laborke.ru/uplcv?utm_term=mario+kart+ds+tricks PDF link annotation
    • http://nexxosrealty.com/userfiles/files/6781245163.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/59839273598.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdc81e88cd---52578385095.pdfIn PDF document text
    • http://licausi.it/userfiles/files/8914762862.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/vumevogonaletafimuj.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/51854185803.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/ferebaj.pdfIn PDF document text
    • http://a-pluset.com/userfiles/73546164242.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/gajudazapuwemujero.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/lalod.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613746cee1d8d---zexibulim.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/29314489254.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/55382315595.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/6jpd218greq8rt9tnev8453bkk/wabite.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109041757345696.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/11387457067.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/75627634251.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/19700321594.pdfIn PDF document text
    • https://dampinggame.com/calisma2/files/uploads/18654000551.pdfIn PDF document text
    • http://buren-kompanie.de/userfiles/files/874803441.pdfIn PDF document text
    • https://domilot.com/uploader/files/26331693514.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-6/20210906111447392120.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/keseviresekoja.pdfIn PDF document text
    • http://megalaserasia.com/upload///4004358443.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_off0000d25e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD25E 18136 bytes
SHA-256: 568aaaffeb9a5ae0a500ec07d9c32636b961eeb502438bc679065b3302e15995
font_01_sfnt_off000100d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D9 10168 bytes
SHA-256: 11f50a126e7e2a75d763c90f4074786922625db47335e3287dfdb9d9a68e9084
font_02_sfnt_off000117cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1