Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8cefb0789fb3c22…

MALICIOUS

PDF

80.7 KB Created: 2021-09-11 08:17:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b0bcc5177051584c44f62532c1a617ba SHA-1: 3cf4920b32105eea0afa6ec037c447f62bb040f8 SHA-256: b8cefb0789fb3c2240db75714a76c6cc473380fcccb7ef5f1054ffaa662aff6a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

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
  • 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://lltsg.com/uploadfile/file///2021091013061116.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/161393e9124790---penelenoselokiket.pdf
    • http://peneleos.pl/userfiles/file/6630978938.pdf
    • http://omatsuri.kr/data/userfiles/files/38119925412.pdf
    • https://pmms-online.com/assets/file/44705224391.pdf
    • http://mebco.ru/images/file/giwerati.pdf
    • http://thuephotocopytaihanoi.com/upload/files/navidepa.pdf
    • https://www.gurkhasfinance.com.np/ckfinder/userfiles/files/witetegebopuruvubo.pdf
    • http://kondicionery-vidnoe.ru/upload_picture/file/buteranumowavex.pdf
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/jisogedubamafeje.pdf
    • http://bukhatirhomes.com/userfiles/file/wamunisamiki.pdf
    • http://globomax.eu/userfiles/file/jifusalolemu.pdf
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613112bf2c0f2---4472159540.pdf
    • http://driver-jazda.pl/upload/file/nigadi.pdf
    • http://hoteldanang.com/uploads/images/files/4995000293.pdf
    • http://wirtrauenuns.ch/images/file/28181069236.pdf
    • http://fra2ange.it/userfiles/files/wirisufi.pdf
    • http://unicorn-furnitures.com/d/files/98493633354.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bfce686f7a---labomime.pdf
    • http://chandravanshi.com/userfiles/file/76596330882.pdf
    • https://eqonetech.com/upload/userfiles/files/bexofanaparogefa.pdf
    • https://slide-bearing.com/d/files/vodifusanexuja.pdf
    • http://runhouchem.com/upload/files/mejego.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1d1f082b1---fisezajukaninofoxipapex.pdf
    • http://predit.ru/admin/ckfinder/userfiles/files/80173991111.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=gta+5+download+apk+android+obb
    • http://s292376414.onlinehome.fr/datas/imgmail/file/94845139922.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d78e.bin
a56f5ebfc8e06e077903bc4a3f06d91f2bb6a6a3cbeddb9b2e2f3a2febdefdaf
pdf-font-stream PDF embedded font (sfnt) at offset 0xD78E 10576 bytes
font_01_sfnt_off0000efac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAC 16792 bytes
font_02_sfnt_off000107be.bin
ba36c049cd4e698c6d6bf2067e3afa597b08da2d224fd59a0ec0f621ad042813
pdf-font-stream PDF embedded font (sfnt) at offset 0x107BE 17440 bytes