Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1d69cc7feb4298…

MALICIOUS

PDF

91.2 KB Created: 2021-06-27 11:13:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 25c89f2b3a3924f08145bd301301077f SHA-1: cdb2c8974afa4e138bb781025f99e02ce93ebe40 SHA-256: 4b1d69cc7feb4298a5ea161c07a7e12ee4acd208d71cd84f5d2dee0eaa182aa1
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to host or distribute malicious files. The ML classifier strongly flagged this PDF as malicious. The presence of multiple links on disposable hosting and the use of 'utm_term' parameters suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/52399935bfa42c2f4bb40393a7d60a1a/xabarifiradizo.pdf In PDF document text
    • https://rivaflo-south.in/userfiles/files/jitalibegigexewubeze.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/84469397483.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d14283a599---xafijigagugipamudeko.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c13e77a2f72---80948080629.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160906c2c84f04---lajonojokuxadewojovevufa.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b134eccc7dbba1f42e278c6c5113868d/77892164321.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/abb0e46ec20af02bf9ff0379fca20dcd/rijomoj.pdfIn PDF document text
    • http://japan-railpass.info/images/blog//file/beretemu.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d81f22caaa5---61957973943.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4037e450cf---tokawedobu.pdfIn PDF document text
    • http://ylpcl.com/ckfinder/userfiles/files/tunosu.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a868f41fb---vataguxugagow.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/vavevunozasafepu.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/har12hnp0a70gj86m35k5ah716/mamaxixomojufaxavi.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/8212911856.pdfIn PDF document text
    • http://uamarkets.com/images/file/vupelebuve.pdfIn PDF document text
    • https://aedwea.com/upload/foto/26473680323.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/26879034742.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/6032135.pdfIn PDF document text
    • http://caigeshi.com/uploadfile/file/2021061701091273499.pdfIn PDF document text
    • http://olympusflights.com/files/files/ruvunisolenorevenavamumi.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/ptoe6osk2t61q012tnjr2gf521/11725089274.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/4bdfad5402ca39b1d79e0374b87d88e8/kivare.pdfIn PDF document text
    • http://asiancfea.org/userfiles/file/lenoluruja.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/99255450932.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=have+something+done+rulesPDF 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_off0000ff61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011773.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11773 18016 bytes
SHA-256: b2bd927b6e8c4097159fbfb2cd205a7e2a31dbfbae684b187b199d75e2869299
font_02_sfnt_off000146bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146BD 10852 bytes
SHA-256: 987919366d77a67b65f65149852d3c966aec5d782d151a7f767e6aebdfc7c544