Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab91e69ed3e62898…

MALICIOUS

PDF

80.5 KB Created: 2021-09-01 09:25:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0219892001d6148144331e2992aeff04 SHA-1: ad181d1be2dbb90b297dbd4f415d3c78633e5e78 SHA-256: ab91e69ed3e62898368f51eaad744fc8dfa0a99c1227bb0a0e33b9b6a68a4b6a
96 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to potentially harmful content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather as a container for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/t1ro1falki2685h3bgt562j552/86749042134.pdf In PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/51317423511.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/bepudasasesukej.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/38199679680.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/vrdai5m5uorrl4b0rft919v1k7/bekuxefovej.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/22046903783.pdfIn PDF document text
    • https://blv.by/upload/editor/files/71767785366.pdfIn PDF document text
    • https://master-service.ro/images/file/11962510610.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/d880129826ba985b7596580d212fe6f3/kenorotexovovumamebem.pdfIn PDF document text
    • http://abwingsde.com/uploads/files/fokotipomonox.pdfIn PDF document text
    • https://equinox-e.com/upload/files/xitezelofesasixutof.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/d797048e50c1272f16a0ce2b626147f1/42837902790.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/vejijowo.pdfIn PDF document text
    • http://hillcrestneighborhoods.com/userimages/63060566418.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/3913279947.pdfIn PDF document text
    • https://glaze-metalart.com/upload/files/98581726096.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd8514472c---45934086725.pdfIn PDF document text
    • https://argumentua.com/i/file/zijanev.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4748a8886dd1d4cbc1bed3d6392ebfaa/68224332387.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/rikazonoruwo.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a87607ec1a1---bifojutomigavetudu.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/dozozetilimifinakibefax.pdfIn PDF document text
    • http://www.jfac.kr/ckfinder/userfiles/files/duwarukuserar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=practise+and+practisePDF 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_off0000d558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD558 18124 bytes
SHA-256: e0306a59973f8328a917ec1da2c8ca1a02b69d8abba9c44b974f44e2ac3a6435
font_01_sfnt_off00010428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10428 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C3F 10340 bytes
SHA-256: 2af82cc6e2794057200a65373b6aa1f244d24a2ca3781e5379edacaac2aedad9