Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c505328aef765f9…

MALICIOUS

PDF

90.1 KB Created: 2021-07-24 16:01:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c6621ffedcd7e15784fe6b058ed7918 SHA-1: 4cad749bc8c938d4eaf8131bace493a1d758bece SHA-256: 6c505328aef765f92bd145cb0912b9e0662e578920e20e0de874e127267c39f7
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a link farm pointing to numerous URLs, many hosted on compromised WordPress sites or disposable domains, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a vehicle for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://anhuishangbiao.com/upload_fck/file/2021-6-22/20210622161756664553.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/4il55t2v5p46ef6cjgti0hrcif/58667651140.pdf
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b623ae8c672---37246832650.pdf
    • https://harkakotony.hu/UserFiles/file/nexamux.pdf
    • http://hjtech.org/admin/upfile/file/66227321670.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/5725b2318c9f3c337da6b8e9bda37430/94993587076.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/o15uj3gt1uo423ev0ak82o2u2e/47207683222.pdf
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6e8ec6ddb---90391137139.pdf
    • http://myredm.ru/uploads/file/33390028367.pdf
    • https://nevisnews.com/userfiles/wipepe.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609fbaac1ff8e---nanog.pdf
    • http://www.dean-cpa.com/files/adminpic/file/49174737559.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d47bdb4139---fopifitudimo.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d64c2e59ecf---niguganozadotewoja.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607154fa35d60---79706727806.pdf
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/cad0d387d783afefb5f91ce8c5a6a9dc/82246264453.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160991a699ac7b---xufikibibivisuvukiw.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a14e7600fec---tuviditoletejunojuxezuw.pdf
    • http://xn--12cbg9dihj7egda2g6a7dceb1d2cp4nvgf4f.com/datas/files/sakelegu.pdf
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/bceb6e3ab3208a88534a596cc91703c6/79721363171.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ace93ded793---puweb.pdf
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/21fdc5e789fac11b32b8ab5a40a22eff/63296799021.pdf
    • https://bd-sokolovska.eu/userfiles/file/32948678565.pdf
    • http://veronikavilla.hu/userfiles/file/fituxuvuti.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/f6170365f0c945a647667a50b1a474c1/72391698507.pdf
    • http://www.allatpatikapecs.hu/images/file/lakuvomega.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=which+yoga+is+best+for+reduce+belly+fat
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • 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_off0000ffa8.bin
dc90ccc5e7134339c51a1ed91a7605175103bc54942e973a2dc434dc35d7e150
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA8 10996 bytes
font_01_sfnt_off00011936.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11936 16792 bytes
font_02_sfnt_off00013148.bin
11a0d520cd8dede3529d25d2af3647d8205252edf3f33d1fb3f6ae0c24634819
pdf-font-stream PDF embedded font (sfnt) at offset 0x13148 17228 bytes