Malicious PDF — malware analysis report

Static analysis result for SHA-256 d553e5099609323a…

MALICIOUS

PDF

84.3 KB Created: 2021-08-27 17:45:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: df2f6eb5942fa7ab441f5168c4ccbb7e SHA-1: 314a6a509e26bf8af695187225decef4cfd0853d SHA-256: d553e5099609323a6615cd092108e637e3f9f808faaa0bbddbf50adee5c9e115
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. The presence of multiple distinct hosts and the structure of the links suggest an attempt to obscure the final destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082fb4fa4ea5---goragidoxitup.pdf In PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/39b3fb2542424e6b584db3f4f2092748/pujakegavizotijaku.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d06a0b713---73884885358.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/807b605aa6abf5da03c6e61a65877cc1/43578575157.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/2018baa1249697bb34f0978251ffad68/81867346036.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/foteramofazipe.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160db0802c1c72---gubebi.pdfIn PDF document text
    • http://htcable.cn/d/files/1259930572.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/midoli.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/12991669146.pdfIn PDF document text
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ae6c2f5e4---tomujurizigejinop.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/51601887203.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/c762da1dabf4036b3145161ac59bb5c4/monarokujetofup.pdfIn PDF document text
    • https://menu2uplus.com/images/file/nuseruxomabidufare.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f3a5ee5b1---kowanejeruwaguxunonegu.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/7o7u5jioapsejl4md3p3t3p45r/badojarixivawoganuwisiwa.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/e30632e4b40afc8399531f0d65dbe873/wafed.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/678c0732f9795a9220264a29fc44e83f/tulimotepatifuxowalera.pdfIn PDF document text
    • https://glbtrader.com/userfiles/file/rojunawapejuwelimolam.pdfIn PDF document text
    • http://ubest.ru/images/file/15551551709.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/pasujenifunukewunititok.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/nofcopmjiif0ridt00m79kbvbo/3922779062.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/86115346584.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/29972290285.pdfIn PDF document text
    • http://snp-ent.com/files/fckeditor/file/8689397956111852a1825f.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+get+a+smooth+stone+slab+in+minecraftPDF 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_off0000e33c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE33C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB4E 17852 bytes
SHA-256: ac8cff0af1d07fb3eae93b6807e15e8395dfd2a071e908366c58170f83dc86c3
font_02_sfnt_off000129fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129FA 11000 bytes
SHA-256: b607fce11c4c9059fa5b5bd83981011bfe50e6cbe9944ecf4b34003798782912