Malicious PDF — malware analysis report

Static analysis result for SHA-256 a752c4729a2c3225…

MALICIOUS

PDF

77.8 KB Created: 2021-09-18 09:15:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 709bec17491770da3e8574ff8d466802 SHA-1: aa0dbb73d27967023c7bae7288b8fa13f8b352f5 SHA-256: a752c4729a2c3225ccd4dc6e39751eaae0d74092539ba7ef2f065bc2ac2c1a0b
156 Risk Score

Malware Insights

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

The PDF contains numerous links to other PDF files hosted on various domains, many of which appear to be compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of link farm heuristics and the sheer number of external URLs point to a campaign designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/bojuva.pdf In PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/remoji.pdfIn PDF document text
    • http://svx.su/ffile/file/lurekutumikezodirivawewu.pdfIn PDF document text
    • http://sfalojistik.com/userfiles/file/71886757041.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/bukogurenutona.pdfIn PDF document text
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/vewew.pdfIn PDF document text
    • http://gptools.net/userfiles/file/puvepi.pdfIn PDF document text
    • https://sankaibearing.com/userfiles/files/patowi.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614048d999799---lepidari.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/68384960588.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/189d6cdc0c0c43e05947baa8e876bf87/vizud.pdfIn PDF document text
    • http://old.smartplus.pl/ckfinder/userfiles/files/87960619954.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/36212617319.pdfIn PDF document text
    • http://sbriz.ru/userfiles/file/lexemonigaranovatobasuro.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/57cshd40li6t7n2rafrpsgbmqs/42405181625.pdfIn PDF document text
    • https://eravukappalpalli.com/userfiles/file/dewarojipujejofijotalu.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/rusenipomu.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380442921aa---lotimudezaludorivefuviwi.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202109110630553415.pdfIn PDF document text
    • http://hud101.vn/webroot/img/posts/files/62238754882.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/53132251276.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/161309904bb4ac---kadevadoputusuri.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/5c169e0d199fcd903595f183daf20da8/fetep.pdfIn PDF document text
    • http://esistore.de/userfiles/file/17201008209.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=jurassic+world+fallen+kingdom+full+movie+in+englishPDF 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_off0000cce7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE7 11160 bytes
SHA-256: a04c0e40e667be7913f13fbb79a832043d74f238a395bf3bcbf7eed144187a27
font_01_sfnt_off0000e69c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69C 16504 bytes
SHA-256: efdf0bf6cbd020c8dbef12a236ea3a31e7db1c4d7d7752dca62ccbcf465e0330
font_02_sfnt_off000110d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1