Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c3773cf9b627b3…

MALICIOUS

PDF

107.7 KB Created: 2021-06-26 12:51:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6f731c110e13b4547476e15547da84bd SHA-1: 5fbc0753ddd9c2562b6f442efbc1b370039cc2c0 SHA-256: a1c3773cf9b627b3660585720efcaa3dbba880709d1b06328ce74fb8c3a7d6f2
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9756

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://hondatayho.top/img-ngocbao/files/zupozazutuxetovemapib.pdf In PDF document text
    • http://zkojicin.cz/userfiles/file/14465190820.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/20210519/2105192134398539255u0b830mhn8b.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/jolnmma5n7uc30c6hrjgd5crp4/vodezaxu.pdfIn PDF document text
    • http://ropesadventure.com/d/files/nimufo.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/bd64640952a456d3f7fecafdafd9f489/67244107668.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/13253169977.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/07a63d7c6196e0564c1e4b84d64a4f71/jodaz.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/239gs91i3kebbr9vmmb6og3ebg/zuberi.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/nazufedobodugi.pdfIn PDF document text
    • https://blnk.eu/userfiles/files/46852452078.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/21292384203.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/bea50820e2beffae77bdee0e7e266d33/48180301182.pdfIn PDF document text
    • http://sunarfactory.com/userfiles/files/jopixoruzabifefuvesaj.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/41a03b8bf23d153a17227294602fdfaa/98690379779.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a6b01b287---57336544288.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/7adafdbc90c525f3940cbfbb163a37c9/87571049692.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160939f616e606---lerulibewel.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c979262efe4---zosexadizowajafumevirajub.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b49d7f8112b---wovefowadopetusuneteb.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608768bdf2b12---pugixukimomumepimepoji.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f51cf3c2e---32769172799.pdfIn PDF document text
    • https://study4student.com/cache/fck_files/file/38143412841.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/243a7264efe3bdeddb97c34c920e5d65/47583695589.pdfIn PDF document text
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/1981f507a3f48b89b0488dc984d8917d/lefivenivevaxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=meaning+of+hydrographicPDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off0000f939.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF939 26144 bytes
SHA-256: 6e2b908cc5037f19bddac8c77fd9c0bfbb41722edbe9632538d6163c4617766e
font_01_sfnt_off00012837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12837 3464 bytes
SHA-256: a8161c2f5ba9235eb51b4fcc43b6bb219725019365cb8d38f9ec25dfe5ce54ff
font_02_sfnt_off000135b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135B2 23032 bytes
SHA-256: 866cdf9429011e203ccc21cbd8c288291f57b3b4ffc42bc15104e56aeb726b5a
font_03_sfnt_off00016e82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16E82 10696 bytes
SHA-256: f2f478e8d0ff88f49799449974959b082897f99ea1dce2a0ecaa780f2511a286
font_04_sfnt_off000186c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x186C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1