Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5163d1d8aabcbce…

MALICIOUS

PDF

122.9 KB Created: 2021-07-24 02:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 55b236eef9ba07acbb6406eae0fc098f SHA-1: 450e781760f6efa92956e361b77404ca5eba49de SHA-256: b5163d1d8aabcbce9254fd703e524b4d2f6e300493c10aa82618f385ab8064a8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to potentially compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest the document's purpose is to act as a link farm, likely for phishing or distributing further malware. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.toeterloeh44.de/files/76258773374.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/sbg379dtmp5s3sslqn7c78js03/nuzevixowidaduri.pdf
    • https://sanipacific.com/attachment/file/rewevitovebuxefiwidimute.pdf
    • http://mackyz7automotive.com/js/upload/files/40732108308.pdf
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16074ae560b58e---4914822616.pdf
    • http://aliglobshop.com/userfiles/file/sugixisenarizuzikawosegux.pdf
    • http://sherylrobphotos.com/clients/56056/File/28491940817.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1609661618dc15---76110616980.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/343ee167a7b8172afa537be145e2c863/patewo.pdf
    • https://vannordenvastgoed.nl/userfiles/file/4437274798.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce9d9cb7365---57025800404.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090610151985---vojon.pdf
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/dezumubakulubixazewuzupe.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/450355531e13a719dcf2c69f057da84f/redovisujimajep.pdf
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1731b40200---vovoposepox.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/e2bbca8b7c8be369296dbe242f8ea457/30591163448.pdf
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/66238027145.pdf
    • http://3wsystems.com/shipinc/userfiles/files/nojatiximudejezem.pdf
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/8a5a5db326e5438a115cf9d4cac85b37/37631531861.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/a7a72312f10f6d80a569cac4123102d8/majuwuxunududufetet.pdf
    • http://stauarchitetti.eu/userfiles/files/82926449262.pdf
    • http://teplospectr.ru/images/files/dinen.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=shakespeare+sonnet+43+analysis
    • 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_off00017bef.bin
24e5cc73e3474b85f996b3407e22c524b05b89159b0004701e137827158e277d
pdf-font-stream PDF embedded font (sfnt) at offset 0x17BEF 18068 bytes
font_01_sfnt_off0001abac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1ABAC 16792 bytes
font_02_sfnt_off0001c3c3.bin
429170dfc7f4da2cd2f61e04146748bb8890cfb5f190d7873195a0dac9b394ee
pdf-font-stream PDF embedded font (sfnt) at offset 0x1C3C3 10880 bytes