Malicious PDF — malware analysis report

Static analysis result for SHA-256 7123bf991582d1c5…

MALICIOUS

PDF

87.8 KB Created: 2021-07-05 16:50:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: b69e107065d3d04df2f9ac35b5f44c2c SHA-1: 4544ed03fbd6f4d871d2044fe5b575aba24e401d SHA-256: 7123bf991582d1c5812584546c54803833c0560fa675f3c8c1c7f0e7ea45bb78
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These links likely serve as a distribution mechanism for phishing or malware, leveraging the 'PDF link farm points to compromised-WordPress upload storage' heuristic. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, offering no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/01002d67d0d5a7ec992399e770faf639/xulenurobasefog.pdf In PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/2igpval0jdf3qbt9qe2jsfgf9l/73562920623.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/24617be66df71d4b28fe5bb2ded60ee0/nadeforudetaxi.pdfIn PDF document text
    • https://samyenngochoang.com/wp-content/plugins/super-forms/uploads/php/files/me3u271p2ngogh18nmer90342o/54086129947.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160b0519b5c9fb---vazanu.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/36f38381f34eec53528ef10f960892bd/52693989756.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/n6ttj52m8pbco0c20pgpgfrm72/rowovububureboluweto.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/33642980134.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/20f866f4d8bbbeef4851c939d6950edf/nopenoburenarebuguxisode.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/826bd7ca2307cfdad9d76c08f69f1342/65045641263.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/g6ffibvc4a1scia6f7vashg1l7/21922800610.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606c690adf826---vugorenizojosekigu.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/714c19b8eeeeccd04b89353601bd9b64/94032901825.pdfIn PDF document text
    • https://nexusmediation.nl/files/64286840601.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/vinop.pdfIn PDF document text
    • http://togetherwewalkny.org/clients/2/24/2411cc079aa0f0d7fd57f81c6163ecfd/File/81098016959.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/munejugapijefobivo.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/946a7fe3ffc9ad9b62e07bc07c2c5660/wavadesotigunepugun.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/6eb9394231b6c7ade34995f3dd3dad34/zavipenijixofigonubikigi.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a26fcc70f24---47390192705.pdfIn PDF document text
    • http://incucinaconalberta.com/userfiles/files/pogabovemelurawese.pdfIn PDF document text
    • https://www.jscorporation.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8dbe89daa---49349098152.pdfIn PDF document text
    • http://cherishedmomentphotos.com/clients/8/84/84fe84b553acfcd191e166b7401b6f02/File/duwuxijugewimo.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075119eddf9f---78329316215.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=relationship+between+structure+and+function+in+the+human+bodyPDF 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_off0000f4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C8 11372 bytes
SHA-256: f92de3fa5f5b6c53049a21f949d70a914fc995430106f1294fd9088e643e6715
font_01_sfnt_off00010f37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012749.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12749 16308 bytes
SHA-256: 97026fe27c7732ceed9d0db040a24b0161a0d034f0cdb364a98b82a3d6920211