Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b7403f7737031f4…

MALICIOUS

PDF

81.0 KB Created: 2021-09-08 22:25:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8619f5e994b969347f16501e4eed3b63 SHA-1: 1376f1c061dee80e5bedea3a7a6955a11b9e7f26 SHA-256: 3b7403f7737031f42856afda079d96a2f53f429caa5ee7cc8fd09b6fb27dad7a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to potentially disposable hosting, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this. No scripts were extracted, but the overall structure and URL distribution point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://arrhythmiaclinic.com/userfiles/file/20210903195924.pdf In PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/83654201724.pdfIn PDF document text
    • https://shoppingplanet.cityplanet.ro/ckfinder/userfiles/files/58454337733.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-5/20210905214935925186.pdfIn PDF document text
    • https://siahotel.com/userfiles/files/57609968962.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/kosavobejo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f1e685fef---balawibijabizopobute.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/13850827886.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/puferefagoduk.pdfIn PDF document text
    • https://egf.tw/test2/images/file/duvofasof.pdfIn PDF document text
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/nejexefowanuzudotul.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/mijonumizomegufunaz.pdfIn PDF document text
    • https://aristi-trap.com/upload/users/files/63209284874.pdfIn PDF document text
    • https://agape4u.org/userfiles/file/lojalanunusudutaratukeg.pdfIn PDF document text
    • http://dyneco.kr/userData/board/file/bozodewulakusepimese.pdfIn PDF document text
    • http://2013.letnifestiwal.pl/ckfinder/userfiles/files/84369918388.pdfIn PDF document text
    • http://shop-exclusive.cz/userfiles/file/68719890383.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/38671135146.pdfIn PDF document text
    • http://kesifveotesi.com/files/biwowojukulotato.pdfIn PDF document text
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/febolijeribomiramower.pdfIn PDF document text
    • http://morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613745a0824fa---62899701054.pdfIn PDF document text
    • http://balogmihaly.hu/UserFiles/file/82626558702.pdfIn PDF document text
    • http://pokwuttibut.com/file_media/file_image/file/tasigorexebebu.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210907104551103.pdfIn PDF document text
    • https://minjar.mebel18.com/uploads/files/furefokusadufelob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=android+block+unknown+textsPDF 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_off0000d224.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD224 19876 bytes
SHA-256: e3b0ccf027ace0e8f807085b0568fbf3e19699fc13848a7c99be3cc2cba9f7f8
font_01_sfnt_off000105e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011df8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF8 10704 bytes
SHA-256: 3ae3863d20a2aa52dd20b78dbb968e8938ed050fd8bf7a6c193566196d999824