Malicious PDF — malware analysis report

Static analysis result for SHA-256 821f7eb896b10ade…

MALICIOUS

PDF

81.3 KB Created: 2021-09-10 16:06:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 646a6585bc6a5691869de648ca967501 SHA-1: 14a76f1f729b1782203b106dcadecd3431bf3cb7 SHA-256: 821f7eb896b10adeed96ac6b5426b193081cbbc092954468694591fa1ca99844
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URLs, many associated with link farms and disposable hosting, suggests a phishing or malware distribution scheme. The document body, though heavily obfuscated, likely contains lures to trick users into clicking these links, which ultimately lead to malicious content or further infection vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://smidgel.ru/uplcv?utm_term=chikii+latest+apk PDF link annotation
    • http://mobil-tech.com/files/88095622364.pdfIn PDF document text
    • https://delphin-bau.com/ckfinder/upload/files/buvedufavonukajawutena.pdfIn PDF document text
    • https://cvssteelex.com/ckfinder/userfiles/files/niritewutudez.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/74358157831.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/jiwizugavafezalesur.pdfIn PDF document text
    • http://verzorgingsindex.nl/images/uploads/83040933281.pdfIn PDF document text
    • https://nodka.eu/ckeditor/ckfinder/userfiles/files/19354099198.pdfIn PDF document text
    • http://aptwash.com/userData/ebizro_board/file/jufomuxatifojav.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/pilig.pdfIn PDF document text
    • https://trade.inter-ural.ru/ckfinder/userfiles/files/jegukewurijomax.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/babekunosevopuvomug.pdfIn PDF document text
    • http://fructusartis.com/i/File/59977547730.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///77000822500.pdfIn PDF document text
    • https://e-room.co/userfiles/file/57136896439.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/56349879547.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/29485443068.pdfIn PDF document text
    • https://twinslock.com/ckfinder/userfiles/files/binit.pdfIn PDF document text
    • https://razredna-nastava.net/files/dibexubafi.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/gozemuzesagegukedexovif.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/9904590835.pdfIn PDF document text
    • http://zjgjqmr.com/v15/Upload/file/202193858115302.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/redogomujanaguz.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/3d1478c1bd043d8385efc4c738b19d9f/rajevirawaleno.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/liwawuk.pdfIn PDF document text
    • http://mardeestilos.es/fotos/file/6401340018.pdfIn PDF document text
    • http://takramaipai.com/mypicture/file/jiwuwupikidejifamamumes.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_off0000cef8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF8 21860 bytes
SHA-256: cc8918a1409f837241e48d72ae9ee6d10faa47139ffab6095406eb799c8cedf0
font_01_sfnt_off000108a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BD 10148 bytes
SHA-256: 996851a7534e504759396712fc8edc28295026032b7933f3b13a911bc8b9de99