Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4668a846b7da2cb…

MALICIOUS

PDF

77.8 KB Created: 2021-09-18 04:00:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6a4662d8d6e331624a376125162d8cef SHA-1: 7c89605202195d3d3c9e368e782836c7048d4a4f SHA-256: a4668a846b7da2cb8bb1722c27fa0bc66a4c7f7bf4af94c4a010387e9ee1ff65
96 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on multiple compromised websites, directing users to download files. The ML classifier strongly indicates malicious intent, and the presence of numerous links to potentially malicious PDFs supports this. The document body is heavily obfuscated and does not provide clear instructions, but the overall structure and heuristic firings point to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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://arniestribu.com/campannas/file/29974175076.pdf In PDF document text
    • http://thunderstar.cn/userfiles/file/20210916015654669388946.pdfIn PDF document text
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/9282cb9ee2b32ffa114e29720ee40b3a/88559600044.pdfIn PDF document text
    • http://stisk.com/file/42841369881.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/2253061153.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021091417171993.pdfIn PDF document text
    • http://uk-finansist.ru/userfiles/file/lozaluvaxe.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/161330d60367b0---jutaxevukunemerumel.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/99568990346.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411c3357560---gexaniwatekizisabid.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210914083132.pdfIn PDF document text
    • http://suurelepa.ee/data/file/69108762268.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/53238144535.pdfIn PDF document text
    • https://jajugroup.com/ckfinder/userfiles/files/8520157680.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021091514061273499.pdfIn PDF document text
    • http://webursitet.org/Files/file/risanaxilapivimutigomek.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/zafabobekalisesujugobewe.pdfIn PDF document text
    • http://gcsiva.com/files/userfiles/file/lemumudoredutejewakijab.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/29074195819.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16132a5d13d396---jomakizisu.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612eff8e3a21f---67027686138.pdfIn PDF document text
    • http://phatnang.com/media/ftp/file/puxita.pdfIn PDF document text
    • http://leoclubmarsala.it/userfiles/files/96976060430.pdfIn PDF document text
    • https://eastmangroupllc.net/ckfinder/userfiles/files/vaden.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=pokemon+nds+download+androidPDF 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_off0000ca14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA14 10488 bytes
SHA-256: d897f24e1e0c5820d63bd7870abdcc11deceb62fcb528904099f521765a83701
font_01_sfnt_off0000e1ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FF 18272 bytes
SHA-256: 26cc85e199d2334d9812b2a3fe14866bf423c82c04cac177203b7c39e66b9847