Malicious PDF — malware analysis report

Static analysis result for SHA-256 5981b4d0604983f4…

MALICIOUS

PDF

74.8 KB Created: 2021-07-06 21:47:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c538b68eb832655cbffd7c37183953e3 SHA-1: 7b88f8af04dc51f20f17eff321fb2268d06a2109 SHA-256: 5981b4d0604983f4dac8aa6a63480b2f20c337abceb50d5aab2bedf131807def
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to lure users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://synerhu.ru/uplcv?utm_term=find+missing+values+in+ratio+tables
    • https://umartravel.com/files/62839843135.pdf
    • http://adice-area.com/pictures/files/megag.pdf
    • http://ipllaser.in/uploads/xawusuvibadogaxuvaf.pdf
    • https://eseninternational.com/uploads/files/67847019182.pdf
    • http://arniestribu.com/campannas/file/38600924463.pdf
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/0511000938eccb9508bf39d7dcaafb3e/xuxogulupizigabifamezok.pdf
    • https://85097781.com/upload/files/timon.pdf
    • http://canxetaidientu.com/images/file/19331925175.pdf
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5fbf8e7d6---15669891496.pdf
    • https://baoyi-chuck.com/ckfinder/userfiles/files/51510323950.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1606f11840a4e5---30274143803.pdf
    • http://ckpak.com/fckeditor/userfiles/file/linifeti.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a722deab56b---wabijokofadotawuwibaji.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085816242234---posijanebawubiloz.pdf
    • http://videofilm-tv.ru/content/File/71949596030.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16070ef909e1f1---lelujuferulap.pdf
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/fc9e5a50e49984638622fdca00267f22/3195780112.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/78398e8d7f2bf602196495b1746d57a7/gumepexopelokanapepab.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607bca2d592e6---niwelazomuwuwizikowilinok.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b988c428e2e---54354909360.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/c3aaeb4f709864e30762ec7464be6ba3/xaseja.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/8cbrld6db9m47c4sq0irjjalj1/bukakef.pdf
    • https://techielingo.com/fck_uploads/files/69305403236.pdf
    • https://tvmreza.tv/ckfinder/userfiles/files/sigejisola.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/77c570c6dfeb2cb99ddc6a4f07e4127f/74377682919.pdf
    • https://copperscraphandlers.com/ckfinder/userfiles/files/66449751814.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_off0000c292.bin
d4470af1dc98f143bad825a9ddffcdfea000e277b4d604589cfb99d72132953d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC292 10876 bytes
font_01_sfnt_off0000db73.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB73 16792 bytes
font_02_sfnt_off0000f385.bin
afe7a657d31fd593468c427c0667a51b0c98dae7ea21529d1b89edd76c5e2aa9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF385 16232 bytes