Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ec8c530590ce97a…

MALICIOUS

PDF

81.9 KB Created: 2021-08-31 21:01:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 236784244c0ec26a1247d69f46b6a906 SHA-1: 9182122ff76eda543f726b7cb89f128f190f4cc1 SHA-256: 0ec8c530590ce97a686191f3e8dfd63ab247ba4ec729fa7c8e803a64c28e0ed3
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads and disposable hosting, indicative of a link farm designed to obscure the final destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://chcial.ru/uplcv?utm_term=what+type+of+clouds+form+at+warm+fronts
    • http://naucseto.cz/storage/37330538934.pdf
    • http://artistalexanderkanevskyroyalshakespeareglobetheatrelondon.com/clientMedia/file/xotim.pdf
    • https://bd-sokolovska.eu/userfiles/file/vurekuxuwame.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/82el38jqtcv78j5b7g6jcuidt6/45990047516.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/c254ac4be67859a5d65758bb260cbb68/wumefanaxifok.pdf
    • https://ecole-anglais.com/upload/files/zusonuvosejikadimuzaremi.pdf
    • http://remaining-mc.de/userfiles/file/rorazaguwosawezifalud.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/f12c5c6a33d2d1cadedef02500a3bcd2/23578448049.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/a1c8d2b1d9f2f1d957d9612d8bc4a94d/ruvozawufinisav.pdf
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077cb6337224---69740376851.pdf
    • http://allseasonsart.com/uploads/fck_uploads/file/kuvuwiredevuzevoxaba.pdf
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c2a78e92c65---14358727794.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612a33f699f90---86239842418.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/qf2q63e6ck6jln6e95fhlbl60e/nasunujozerigokotumob.pdf
    • http://rulada.by/upload/editor/files/loxelim.pdf
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/1fa7cc8cd7cd5c8c0ad5be22d2c32f79/34360955513.pdf
    • http://bonfiremadigan.com/uploads/fckeditor/file/niwisowosajidirosupegu.pdf
    • http://eltdb.com/UserFiles/files/85106025921.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d54606be4---40520973115.pdf
    • https://vieclamxaydung24h.com/upload/files/48563824800.pdf
    • http://harlit.com/ckfinder/userfiles/files/20210809_181108.pdf
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/88e6439463626c884ebbaddbcc7ce2b3/titewivoxamugabugetoburep.pdf
    • http://bentleyplemtech.ru/userfiles/file/rabujo.pdf
    • http://tramtronbetong.com/uploads/userfiles/file/38281692697.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16079db10c7914---wunizojuxepim.pdf
    • 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_off0000def4.bin
56885e8ad2984f2712410ececffc7ae7b499362b7e038b343e052095d4fe689c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF4 11088 bytes
font_01_sfnt_off0000f8bb.bin
a51d08dea5ac98fa8a0fe9b1ef38c7d999bbb115884ba1bcbd5034e6f790601f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8BB 15976 bytes
font_02_sfnt_off00012199.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12199 16792 bytes