Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9558c912bac5e8…

MALICIOUS

PDF

92.1 KB Created: 2021-07-04 11:50:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 770e67146e07aa033bbc98d920acd01d SHA-1: 49ee3118cccbea7f211bc4b6e012335f502e18d2 SHA-256: 4c9558c912bac5e8fa8dc126f57543191970d589b5fe96be137755763c9e70a8
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which appear to be compromised WordPress sites used for hosting PDF files. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to lure users to potentially malicious content or phishing sites. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://crysiq.ru/uplcv?utm_term=shattered+throne+matchmaking
    • http://bmcnx.com/userfiles/file/botogorokuwapatada.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160807c4b05271---94876114424.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/e11b2f7cd67eda81404408c369f117f9/gibetalomisixelutokom.pdf
    • http://mojahotels.com/ckfinder/userfiles/files/40052490074.pdf
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/a8eae91d919eefc2828d6890b2d46688/18260700916.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/a8a9147caee22f55a7b28828f5cee472/dolefosegonoweg.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4de62cc9f.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac9f4b122f---zubugetidat.pdf
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608187102af93---81416781517.pdf
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bf3e1303a---34426848708.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/33c2bfe40d57f60b1e3d5f4690357688/15545556769.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a417069e0a0---30701341793.pdf
    • https://aprilboya.com/userfiles/file/teneb.pdf
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/jaghvro6pflpm6iq12s5fp3l7p/98563504855.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/160cca826565fb---dobufomegojaja.pdf
    • http://climacom.eu/userfiles/files/wegagalap.pdf
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/dg9mi8pn0kapl69665tavhj9p2/rejixajubatoga.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/31bf429d6960f4baaa13e196db1fae5a/92624216019.pdf
    • http://tuzvedo.hu/elemek/file/wanunudekafunepimibamu.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/20b1943527edaae3a34d118abd7cce77/neboxutovosuxikaxusuxones.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/f7eac3d85e7ba4e9116a0b68f313ea7e/rinojikobidotonibetagak.pdf
    • https://ferado.vn/userfiles/file/49103247317.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa00d05ccc---tipomegibasuzotevu.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b85a2b395c0---66046696215.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_off000103a4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x103A4 16792 bytes
font_01_sfnt_off00011bbb.bin
10c7fe7240bf5ece6318025119e9c7382d8eabd695e2df8247cec1e672402720
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBB 10772 bytes
font_02_sfnt_off0001341e.bin
30d4172c018694d21785b4a13ec00195c36652d54218888ab2fa4c39c86e4ef3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1341E 17260 bytes