Malicious PDF — malware analysis report

Static analysis result for SHA-256 934bbe466eefa379…

MALICIOUS

PDF

88.2 KB Created: 2021-09-13 16:04:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3ca180719bf2f8bc29090448c6a6cc58 SHA-1: 3ed4d4746febf9cb41e281ac40fbab39f44a963a SHA-256: 934bbe466eefa379847c9c211f39fdad8bef3269ea87b637d57db32d90f81a8a
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier flagged it with high confidence. Numerous heuristics indicate the PDF is a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

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://aquaclub.hu/userfiles/file/taruxulu.pdf In PDF document text
    • http://prabashproperties.com/ckfinder/userfiles/files/41197019118.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/9625556161.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/24212140720.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/muzowibakirozekiteke.pdfIn PDF document text
    • https://kingdom.vn/userfiles/file/86741716861.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/cfc830e231426b0daf72e2e0382c4072/jovopapesavafeler.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/89300961591.pdfIn PDF document text
    • http://itagqatar.zajeltel.com/itag/file/files/15011638166.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021090515555029.pdfIn PDF document text
    • http://gartenstadt-apotheke.com/userfiles/file/36803638909.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/55720536659.pdfIn PDF document text
    • http://panel2conso.com/userfiles/file/mumozixuxixuzawelez.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/virulamimeviwapum.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613ef5fc8016b---71186553320.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/sakabipu.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/d967664c998844c63e041b98e879042b/16305580331.pdfIn PDF document text
    • http://punaide.com/userfiles/files/11395229913.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee15fc5e0f---turokofunajunezod.pdfIn PDF document text
    • https://matratva.in/userfiles/file/45090567074.pdfIn PDF document text
    • http://ambiance-cinema.fr/wp-content/plugins/super-forms/uploads/php/files/83b3d5d07f62acf35a934e78d4bf34f0/tukapidawofu.pdfIn PDF document text
    • http://zhihepvb.com/upload/ckimg/files/202109010630545966.pdfIn PDF document text
    • https://granitabrasive.com/editor_up/29815127600.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/78386685141.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=mime+type+for+apk+filePDF 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_off0000f741.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF741 10444 bytes
SHA-256: 2d4986e9b8c95d135ccba79ca9001270ece52e4359ec97d84fcf9a4a3cbfa44a
font_01_sfnt_off00010ef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF9 16868 bytes
SHA-256: 3621888b8154c45b6f5ab01d76dfd635ad42faa19111192fb6d17ad2557b708d
font_02_sfnt_off00013ae8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AE8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1