Malicious PDF — malware analysis report

Static analysis result for SHA-256 51605d857e5fd4af…

MALICIOUS

PDF

106.5 KB Created: 2021-09-06 15:49:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bc93a5f6f9ec6d31ac47347fc25f61f6 SHA-1: 8276a19c722afdbaf7ff33c0f67030dc84369ccd SHA-256: 51605d857e5fd4af8c1498ce4d1e9e67588de1016d3f71a3af167a24a21e87e8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. It also contains numerous external URIs pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://irlanc.ru/uplcv?utm_term=analisis+beta+karoten+metode+spektrofotometri+pdf
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081aae59b6ec---zekaxorikinubemujebi.pdf
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/7fc8bb8aae5e9ba225e21bcc13b9c38c/51637347818.pdf
    • http://ventilatoryzlin.cz/images/file/luxekeminipifivanimesab.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/21b0fd53193410479b7f8508ac5592ab/pumupifatakodoniside.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/ra3mje2ipec00u7oj7ailk7kp6/xebodenukegobagudek.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/20c95b89665aea13923826ad8d9d4b3f/nujotazigojagoto.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a942c6f5ef---texofated.pdf
    • https://giant-nano.com/app/webroot/userfiles/files/gilemadodi.pdf
    • https://oteaexpert.fr/cite_imgs/file/romiwebafomupapifozos.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fc0bfbbcfd7---28699900240.pdf
    • https://kaisar168.com/contents//files/10066362107.pdf
    • http://cungcapbaoduongcuanhatban.com/upload/files/sazovuma.pdf
    • http://garderoba.sk/images/_file/zezoxijaxilusemi.pdf
    • http://phuwangnam.com/user_file/file/kazopuvoveduzanixawad.pdf
    • https://daleel.global/wp-content/plugins/super-forms/uploads/php/files/qge8q9koe1qma4ssej04hmo3mf/tekobizelanigokal.pdf
    • http://mastera-mix.ru/ckfinder/userfiles/files/kudow.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/wenite.pdf
    • https://carlojans.com/cms/file/xilefokuturasarulipixu.pdf
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/5667201979.pdf
    • https://beauty-full.ru/uploads/files/60896953228.pdf
    • http://porpora.biz/imagenes/imagenes_contenidos///xogibozunoxe.pdf
    • https://genegurumiraclehealer.comuserfiles/file/46453736038.pdf
    • http://rothemtour.com/FileData/ckfinder/files/20210715_59549A0E95A4FC53.pdf
    • http://clubesquilacoma.com/uploads/files/wujiredunabakivawoz.pdf
    • http://pogotowienaukowe.com/Upload/file/78401523110.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ca9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA9 16792 bytes
font_01_sfnt_off000124c0.bin
9dbf55d9dc29f9cd996c977e729ea915660f29401024d7084a9c4a56c22c6cf9
pdf-font-stream PDF embedded font (sfnt) at offset 0x124C0 10872 bytes
font_02_sfnt_off00013daa.bin
3b47819d631aa4b239230c7f9722946381a6393798b62cab836cae5942ad4111
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DAA 16692 bytes
font_03_sfnt_off0001556f.bin
cbee262fda5ba033abea9c6ed61bc8cc1a03af8e087dce557dfd1803b8b99a48
pdf-font-stream PDF embedded font (sfnt) at offset 0x1556F 26432 bytes