Malicious PDF — malware analysis report

Static analysis result for SHA-256 5545d1acc833cef8…

MALICIOUS

PDF

110.9 KB Created: 2021-07-13 20:25:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5554512a4824110938938fc5f8a716ac SHA-1: 88f2faa0c23bda4e1b4873aee150e94ebf580a41 SHA-256: 5545d1acc833cef8f53e92867fc4eeb9d88e3a1424bb16a13244fac851077c9a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the link farm and the detection results suggest it is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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 https://nomylo.ru/uplcv?utm_term=ibn+an+nafis
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608505e4de8a9---defivijogowokan.pdf
    • http://dianacb.cz/userfiles/file/gomizokafejujaxedef.pdf
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/lubuzedofenil.pdf
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/1bdd10ca25031ec43c6ed4f32a07cc9b/nuferakogosojuzoge.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3285414040---rofumadef.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/a221825e75a88f3f13157ac1a2f2c7d0/dinitotoziwixarewokib.pdf
    • http://tulsamemorialclassof71.com/clients/84987/File/85192103069.pdf
    • https://abofahed.com/userfiles/file/vekuwusinebepi.pdf
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/d6krtgtkkavdd6edg5qq6rn58a/30134113746.pdf
    • http://creptiles.dk/userfiles/file/xagajonadopazuse.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b480462bc8---vogiwev.pdf
    • http://russia-ex.com/73031201301.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc26e038d3---55503597159.pdf
    • http://dade666.com/userfiles/202106file/2021061813200570554.pdf
    • http://seigyobannkaigaikikaku.com/ckfinder/userfiles/files/69782376659.pdf
    • http://crystal-lamp.ru/uploads/files/37380225719.pdf
    • https://bataretak.com/img/files/file/79467961926.pdf
    • http://glamour-nsk.ru/ckfinder/userfiles/files/20661218255.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/6g7vao7res5kl2lrh2luduodcn/74240208424.pdf
    • https://assignmentmart.com/ckfinder/userfiles/files/34241920722.pdf
    • http://hotelamadeustorino.com/userfiles/files/xinetesumuzugimixuwilakib.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
stream_002_off00012b81.bin
2706affb0614efda41eec9690d7d866eac5c02dcf75d9090afe009a6f3082873
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12B81 21916 bytes
font_01_sfnt_off000151cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x151CF 16792 bytes
font_02_sfnt_off000169e1.bin
945be17775f7064d4157448e5c3022e79edbd9f4764b4719633a7b2cecbf0c35
pdf-font-stream PDF embedded font (sfnt) at offset 0x169E1 18728 bytes
font_03_sfnt_off00019905.bin
aac9d199671168326fa50075a549cd368b214b600afd0336a5c522205f745c99
pdf-font-stream PDF embedded font (sfnt) at offset 0x19905 9800 bytes