Malicious PDF — malware analysis report

Static analysis result for SHA-256 25f3369ee5f70662…

MALICIOUS

PDF

86.4 KB Created: 2021-07-17 19:33:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91af7fc8f7107db3c7161b21ee01e082 SHA-1: 4aceac0263e42d012972d3aab709675af63c6d91 SHA-256: 25f3369ee5f706620f5b32ccbb69e97d55fcc108be483d0063a8592f54c3e766
196 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with high-severity heuristics indicating PDF links to algorithmically-generated URLs and compromised CMS upload storage. The document body is unreadable, but the presence of numerous links to potentially compromised WordPress sites suggests a phishing or malware distribution attempt. The primary IOCs are the suspicious URLs found within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/f9f6140cc0101f59f16694747b11176d/dotonobimuwifemuxililot.pdf
    • http://akcjonariusz.com/UserFiles/file/6658438451.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/67f4c76cc290f8628e8128c65438ddaa/58139304807.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/hnch7q7hsqhjg6qlvnvq5qimt2/wiruje.pdf
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093b5184f545---vunisibagites.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/0778a9904a46df6f934ae87f878fc359/muvasuvukijede.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/7dcb2629e308d5680b932136cecda99a/julatixojulusemubugebidik.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/46oma4ep8qmc6cqfc61c2bgso0/kosakozozibadowa.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bfc9c66653---dumejitu.pdf
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c95779cb8e4---topomufuxo.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ceff13f03d---dinikazexiruvuzobisa.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160f303ee12cac---guxipakizedodaligu.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/3b2faaa96ed191e01f8d4957d88dd2d2/negewikusemubu.pdf
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/051f7bfbbbc61a0371e36a1088266e2b/46187917777.pdf
    • https://a2designbg.com/userfiles/file/72941651586.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c3855debecb---38824974463.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607deeac96156---2820858473.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba00c86dfb2---73446434210.pdf
    • http://argyleliquidations.com/userfiles/files/deruwukitebixitorufuzoni.pdf
    • http://garderoba.sk/images/_file/85924949639.pdf
    • https://ntpuvoice.com/ckfinder/userfiles/files/64924891328.pdf
    • http://www.themixchange.com/userfiles/files/xakulunebilimob.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160d756118343f---78911885910.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=560mm+to+inches
    • 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_off0000f14e.bin
a7cf4e63a715a6d6c6e0a5f0aace4e71f5cea889b96270d19c798453b1390f86
pdf-font-stream PDF embedded font (sfnt) at offset 0xF14E 10516 bytes
font_01_sfnt_off00010911.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10911 16792 bytes
font_02_sfnt_off00012123.bin
61f309e94e6772a6a056d1c405f066890ae0d65385a744af321003bb4c2c4eba
pdf-font-stream PDF embedded font (sfnt) at offset 0x12123 16776 bytes