Malicious PDF — malware analysis report

Static analysis result for SHA-256 79d38e6b7c5591a0…

MALICIOUS

PDF

77.3 KB Created: 2021-09-04 03:34:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 753584f98b9a8ccaab8d621d44202380 SHA-1: 7ce34a7540bbf07ee133d78771a1b9ac167eb4e5 SHA-256: 79d38e6b7c5591a08a26e1e5db7d66ed63557f56c5b5c5eabc9c532499bb821f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, with heuristics indicating it is a link farm and a potential invoice lure. The document contains numerous URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting an attempt to distribute malicious content or phish users. Although no scripts were directly extracted, the nature of the URLs and the 'invoice lure' heuristic strongly suggest the document is designed to trick the user into downloading a secondary payload or visiting a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://intrinhgia.com/admin/webroot/upload/image/files/besuvezopiregixom.pdf
    • https://machnhaduong.com/images/uploads/files/50178186541.pdf
    • https://mariellatriolo.it/public/file/94049512730.pdf
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a889608fd---18163717993.pdf
    • https://shipnhanh247.vn/asset/files/tuxowixafagoroz.pdf
    • https://accounting789.com/ThImg/file/51827596239.pdf
    • https://pearproperties.in/userfiles/file/palekazakajubiravo.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/e2jolakimeqqtn1kmf0qrdpc4g/51501861983.pdf
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/6d208390bc7bf5851858a53e77439fe0/61052661017.pdf
    • http://smflow.in/admin/uploads/file/19024031105.pdf
    • http://ptairsupply.com/userfiles/file/49823112525.pdf
    • http://brilspa.ro/userfiles/file///pafefuwuwuxelozarob.pdf
    • https://gulf-rope.com/images/bulk_images/files/nizolukugi.pdf
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ab169311c1b---62098624000.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160f9d09175095---waxixufesubejadaki.pdf
    • http://ha-sine.com/d/files/kulabixajudosokemopevab.pdf
    • https://aprilboya.com/userfiles/file/notigikiduwovesavapala.pdf
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a06ca3a2690---57466703571.pdf
    • http://bluebirdcanada.com/FileData/ckfinder/files/20210827_A7CDECE50ADB7CC4.pdf
    • http://nesthomes.in/userfiles/file/79228405911.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099cae7104e0---bujezufud.pdf
    • https://www.institutvzdelavani.cz/files/33198022760.pdf
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1610d5d86524cf---44763587159.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=negative+impacts+of+unemployment+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_off0000cbf0.bin
db0cc71ec6d67a575cd064787be2f2eca61630c4079c0c2b81993ba578e2977f
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBF0 16404 bytes
font_01_sfnt_off0000f56c.bin
6274b408ed57834241a82b31d76a9951a12388a04b661a6d461d2c9687fe0f61
pdf-font-stream PDF embedded font (sfnt) at offset 0xF56C 11120 bytes
font_02_sfnt_off00010f3a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3A 16792 bytes