Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7bfd12af194d82d…

MALICIOUS

PDF

82.3 KB Created: 2021-09-18 01:25:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a6dd3086831ebaa8b4173347e465c3ff SHA-1: 9829993af1ad680a5ca4c202e6ed8f71c2966f91 SHA-256: b7bfd12af194d82dd90eb89371f0736d002d73039933ea7da0b1d02749e57b96
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm and a lure for password-protected archives, a common tactic to bypass security gateways. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://twinmd.ru/userfiles/file/ritujevexosuderib.pdf In PDF document text
    • http://royalwedding.jp/images/blog/file/xedovesufuxuvifepesowaji.pdfIn PDF document text
    • https://wheelmartthailand.com/image/upload/File/4179605205.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/40116357152.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/57984403722.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/jerugokapudebiga.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/sabolofiruvumelu.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/75626841899.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/bb5f270741b4d8c1e5bcf1414b208819/lorobejud.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/desomebukitusotuwezorapav.pdfIn PDF document text
    • https://bilalyapidekorasyon.com/userfiles/file/zabelolemogopipi.pdfIn PDF document text
    • https://kawanmto.net/contents/files/vapebitejowakat.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/77774492657.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/9770a5153f4f86ad6eb6fc4d38eb9e42/94824410840.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/b476fbde13a53220f9ec1ff1ed84bfb6/97624460990.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16137aa2e86b37---tidasipevemawegozatuzekir.pdfIn PDF document text
    • https://mosallaesf.ir/uploads/ck/files/58050054194.pdfIn PDF document text
    • http://tjtvina.com/Upload/files/nenurodirexuwaji.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091010125694.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/gedelerokakudopufer.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=gta+san+andreas+highly+compressed+for+androidPDF 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_off0000dc0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0C 17688 bytes
SHA-256: b23383ae72f2f0feb6b6bdc29f812670e6078bde29acd4b09f2e837fa5657b73
font_01_sfnt_off0001098d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1098D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A4 11220 bytes
SHA-256: 73ff3c4037938dbcb2797977e769008d06d4bffde979575ac6b8a3938d17cedb