Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8bb53b4e7159e68…

MALICIOUS

PDF

77.7 KB Created: 2021-09-18 20:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 25ef57776110400af0417e7b4b0dcc00 SHA-1: fa774217424b96508c7d2a621519112be5e59e76 SHA-256: b8bb53b4e7159e68d40a41d89b355ce6707b50207c045339b9868f1faeb90813
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to other PDF files hosted on various websites, many of which appear to be compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through these linked documents. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the interpretation of this file as a lure to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://pistant.ru/uplcv?utm_term=tiktok+apk+latest+version+free+download
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/ejd58d4vrltvas8h39up3ee15g/46932299213.pdf
    • https://xn--90aweabvm.xn--p1ai/ckfinder/userfiles/files/45799456219.pdf
    • https://atasuorganiktarim.com/upload/ckfinder/files/55648180471.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7c480096e---fimijinigotuzafek.pdf
    • http://aarogyamedico.com/userfiles/file/kopigixugas.pdf
    • http://koovappadyscb.com/ckfinder/userfiles/files/57640504836.pdf
    • http://baozhaopharma.com/upload/files/85431586988.pdf
    • http://wjcopy.com/upload/files/kafedinemuluvirerax.pdf
    • https://edinburghpools.com/contents/files/vapajedivagefit.pdf
    • https://navliecky.net/userfiles/file/fujunadukosifiganilax.pdf
    • http://tayles.com/uploaded/zapabowa.pdf
    • http://tayles.com/uploaded/32820970398.pdf
    • http://studiogiovannone.com/userfiles/files/61228551951.pdf
    • https://sieuviet.net/webroot/img/files/27954174360.pdf
    • http://cdmatik.com/uploads/file/sofitakelux.pdf
    • http://prota.ru/upload/files/vamagiku.pdf
    • http://matchonusa.com/uploads/files/nonevakinetorebo.pdf
    • https://aymsoft.us/aym_image/files/bizagosago.pdf
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/a49177debe85ed6e1133d6026ff8e4d2/45006026654.pdf
    • http://radissonhoteltraining.com/userfiles/file/labalababatu.pdf
    • http://turar-mussin.com/userfiles/File/sesolepese.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613908cbda749---5549138635.pdf
    • http://www.pethouse.es/ckfinder/userfiles/files/18382946025.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cddc.bin
5ca10e32816343d2cd836cf7332cf483f454a41c96280557791a4081cd414c62
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDDC 10700 bytes
font_01_sfnt_off0000e69f.bin
bee87b6cf845001f45272e0c2e7e7d97a3879879668471c80f2dc7a2182955ab
pdf-font-stream PDF embedded font (sfnt) at offset 0xE69F 16400 bytes
font_02_sfnt_off000110bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x110BB 16792 bytes