Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c8a3b83f7b211e7…

MALICIOUS

PDF

106.5 KB Created: 2021-07-16 19:20:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ed25f3301acc2a7cdb2a03e1b0d4e88e SHA-1: 3ef840c1d36c4a949106a990decc1228eadb3219 SHA-256: 8c8a3b83f7b211e762fdbfe026717d6b1418de4b3296432d178dd876c6f9b28b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised CMS upload directories, suggesting it's part of a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://activepymes.com/pub/file/nuzigaxubi.pdf In PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092cfa26af0b---43806037773.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3603d1c3b---52410044432.pdfIn PDF document text
    • http://haciogullari.com/depo/sayfaresim/file/76823798579.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/d7d016708d85830d00b6a6cd52d4e992/kovakizobubuxivizis.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/makokukogiriladebenowit.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/e9eergeo05grt6ae3s9fsmnrsm/sewikubiribejewogus.pdfIn PDF document text
    • http://wf515345.tw/CKEdit/upload/files/rarixaman.pdfIn PDF document text
    • http://eltonltd.ru/sites/default/files/uploads/tiwuserejemixenulowegi.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc1a8019ea---nelimixoboruti.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/34976310154.pdfIn PDF document text
    • https://didacostruzioni.it/userfiles/file/2913158783.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1769c25033---setigupodomumutelo.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16076ec3629ccf---58061637060.pdfIn PDF document text
    • http://andrewsexes.org/clients/867461/File/bagojudejagapikimu.pdfIn PDF document text
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/121510524.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/nepalodebavapazuzulabara.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/16088fc4c1afaf---94772616977.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/660ea4a3a53f58c893e297df1893d377/ruzupukevovu.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2af94e096---20185060704.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/uhdcu6336d87609v8m0uksldh4/vesamiwubel.pdfIn PDF document text
    • http://shsuorui.com/uploadfiles/fckeditor/20210613/file/16235621888932.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/47a578c3399bfeccde00b37ec4f116da/79708903168.pdfIn PDF document text
    • http://makingthegradetexas.com/clients/d/d4/d4716c73f098ea79da165a2194b6736a/File/87368100519.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=early+and+late+postpartum+hemorrhagePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013b4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B4E 18324 bytes
SHA-256: 9c8705968fdf3bf0bfca611c51bbe5258611c83edeb60da042e31764b5feb653
font_01_sfnt_off00016ba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16BA5 10944 bytes
SHA-256: f482a2b9b9ea1723d57e23c0e85b9e3f770bbe5c6622ad7b090ba47fe91d9ad6
font_02_sfnt_off000184a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x184A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1