Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4137ffb86ef269f…

MALICIOUS

PDF

82.3 KB Created: 2021-06-25 12:56:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 4286eb3654d8e59dd0f5df48a1a48a9e SHA-1: 16e137e14a4b5f1f7f3ede26a376d4798ecacae5 SHA-256: a4137ffb86ef269f321d671e5e65d4dd9d9ae8fa327f69c389cf0acf0a330803
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links and the 'link farm' heuristic strongly suggest the primary goal is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/add363ed81409b97065ad9463ec65497/luzasajobiretebonetif.pdf In PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/aea96fab0312c558885194606ab89d45/toluborarolojero.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ad3c5b039---gedepepojinevasulub.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c1b22046f---39400783370.pdfIn PDF document text
    • http://jamessham.com/admin/usercontent/file/37953870250.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c31b0090a4f---limifonavafifij.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cef8b413fe---25761578369.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160701689c9e38---16492884735.pdfIn PDF document text
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5fd52fd79---pituveb.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/87498242235.pdfIn PDF document text
    • https://myveolife.com/wp-content/plugins/super-forms/uploads/php/files/359d9c368eacd90c07820e21c31a0506/nurotozok.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16075ae8a42939---24503624404.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/ijamivilikavemewunopelu.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c71b5766ec8---miwexikigezedo.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b391991d1---41491500378.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=maytag+gemini+double+oven+owners+manualPDF 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_off0000de0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f61e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF61E 17144 bytes
SHA-256: a86ad43efe3546b207f50a253058d48a25016f96b1710acc6c8e1404f17caf61
font_02_sfnt_off000122df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122DF 11092 bytes
SHA-256: dd1fccb21cd6ab2be4a9fc0d2e95497ad2a4653daacc08f19bdd25fd463540e2