Malicious PDF — malware analysis report

Static analysis result for SHA-256 35f9f890b1b35efc…

MALICIOUS

PDF

79.1 KB Created: 2021-06-29 02:57:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ad55b83f985e7a26f545db710eeaec11 SHA-1: 6df3e65204557ed4889c5a9d09f077a139b0a485 SHA-256: 35f9f890b1b35efc3d9a16dd887d941154cc0bf5f66884d08cf6f6fd6a327e4f
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and other domains, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URLs are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://laborke.ru/uplcv?utm_term=another+word+for+somatic
    • https://floridainvestment.cz/files/file/rizexixixadalav.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7e452ad37---49223752805.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebd46d51e0---mukibawokomirobubawa.pdf
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607aaef861572---jopopemerowuxadifubiku.pdf
    • http://liubeauty.com/luutru/files/11758086270.pdf
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6475991492---97476905830.pdf
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/ae18604e56d3ba3c0c2486985a9980be/92693325846.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a775c4a1650---daguvukirik.pdf
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/9i9fl96uf7dfuue7gpkubmcl2j/kulalokakuviponovun.pdf
    • http://alumcity.ru/userfiles/file/novuwijixebabifu.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ee73v2nuckmm1e089at5qhfl8q/bolaralu.pdf
    • http://jaatkinson.com/userimages/76437944006.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/0d7f87205a865197cee5fe9818cc0d5e/81416367314.pdf
    • http://meteosputnik.ru/userfiles/file/mereze.pdf
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/padologimo.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16071352ef0e33---jujaso.pdf
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/160798aa71730f---palugabomimalunakagasogaf.pdf
    • https://acgroupenterprise.com/userfiles/file/dinosopufogubavajomonude.pdf
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/g81hl2ce4g2c5f3e9mv204l524/16987438728.pdf
    • https://guijek.com/userfiles/file/19637467202.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/f244eh9ssd4sgigi8tbakjqgft/birazagutaba.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa083f84757---jusetip.pdf
    • https://annjulieskarpmo.com/userfiles/file/momuxuxulo.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_off0000cf5b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5B 16792 bytes
font_01_sfnt_off0000e76d.bin
ea7f26bac931c6b73aacf767632df5999718734b67d22ba80724b7d9307c94b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE76D 17420 bytes
font_02_sfnt_off00011502.bin
09183cb30c1d49d80a85027dbf5e9874fbefadd47baa167eec6fecb5d0fd03b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11502 10760 bytes