Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef467a23761131e5…

MALICIOUS

PDF

83.9 KB Created: 2021-07-04 19:12:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f86542ca0cf59674e55acac268545510 SHA-1: 8f28eed1d5eb4626d3c8d0e90d07a7c6104ce146 SHA-256: ef467a23761131e57559b8470d53d2d09e2bc289f253273252511e6896bc1e55
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple compromised WordPress sites, likely intended to redirect users to malicious content or for SEO manipulation. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports this assessment. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/4innnjns1apu91lg0baai60o5n/74472469486.pdf In PDF document text
    • http://stattus.com/assets/file/xuzigodeziju.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/e65ad4f3f749dc53179c9f7d8ac9d44f/2341000967.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160865c03b0ce2---8304190878.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160864ba88f970---61617094236.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202106/file/1624381302.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/ef921f5e3bf4446e23f109963ab17403/fitosininiluz.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/f1ec6ed5943cd7007c70001416754501/kumeporowuvodewi.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/dafab.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a28d1387c0a---9841395719.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d46150bbd0---86780667685.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1606d901bcef55---55723115160.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/0e4a6092434ee8d7c860349b4a0e15c2/51997835916.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/160963f4b4092f---96858064287.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/3d21034ff957fa1e40faa75df2ab2f24/ruxuzujab.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e0784885126---natodunoloneso.pdfIn PDF document text
    • http://k1a.ru/images/files/file/gujizazorife.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7b3e70600---53222336139.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160c582ad25120---63674646828.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760445a1c37---xodowiwovoxugemezifezosu.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084ebc3466f9---89489300574.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c878dc341e0---towugusegopi.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/16095c4e1ba06d---xafinubijep.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9cb9c98192---vomig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=confectionery+products+handbook+pdfPDF 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_off0000e4bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BB 16888 bytes
SHA-256: de9ae7b5a0dc3377aef12fa0c7d5d55a6b1e91cf39c91511980faff90bc36d1a
font_01_sfnt_off00011071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11071 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12888 11148 bytes
SHA-256: cdaac196412ce918dc80c3bf4933bea0f1596e035334975230ee64929df71559