Malicious PDF — malware analysis report

Static analysis result for SHA-256 81edf37316e7e0c0…

MALICIOUS

PDF

70.0 KB Created: 2021-09-30 13:47:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1d884f0ff8ea0898967ca1d7567ab9fe SHA-1: f7af546e2a64618bd3b9f0f3e62d86a8b3220591 SHA-256: 81edf37316e7e0c03fb20732c36f332465c0c490106d31f4c488978a3b5631b2
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous embedded URLs, many pointing to compromised websites or disposable hosting, suggesting it functions as a link farm. One URL, https://allytemp.ru/uplcv?utm_term=true+skate+all+parks+unlocked+apk, is particularly notable for its obfuscated query parameter. The primary goal appears to be directing users to external malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://allytemp.ru/uplcv?utm_term=true+skate+all+parks+unlocked+apk PDF link annotation
    • http://kerekesvillszer.hu/UserFiles/file/jiresipapuxazonabemig.pdfIn PDF document text
    • http://zaiger.ru/img/file/kumeragutevozanagipebaku.pdfIn PDF document text
    • http://newabel.com/ckfinder/userfiles/files/41111013823.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210916_172142.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/57831590803.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/32574582561.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/vssv4a007lfarc52g7m3528ivt/zivodef.pdfIn PDF document text
    • http://alvit-bk.ru/userfiles/file/99113639349.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/mixuxafelabezunibexadiwox.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210905115114.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/20563801692.pdfIn PDF document text
    • https://bimore.vn/webroot/img/files/34841141389.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615434181f13a---tigepivofizagoxukajoxobo.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161493c4d2b453---xepusowopodeton.pdfIn PDF document text
    • http://fizjoactiv.eu/Upload/file/vidupabotogelatimov.pdfIn PDF document text
    • http://universalestetic.com/userfiles/file/52758864493.pdfIn PDF document text
    • http://parkety-patemal.sk/files/file/98042306316.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/moxemifesutidezepajivole.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/45579007198.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/6ad0cb5bd4ca9c4a580a5024d003529b/11953683054.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16143dcc30444d---54251887614.pdfIn PDF document text
    • https://suacuasathcm.com/uploads/files/42263915937.pdfIn PDF document text
    • http://xn--franzsischebulldoggen-lec.eu/userfiles/file/10299176666.pdfIn PDF document text
    • 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_off0000b1d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1D2 15528 bytes
SHA-256: 8479fa1a3d83c4596d5fda41e1bb0bfb08b7c17ded356b615983577826c930c4
font_01_sfnt_off0000d9a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A6 10572 bytes
SHA-256: 988e2aa751fed9f7d1421fc8c32315d482503abafe8ec8968d14dc946d574801
font_02_sfnt_off0000f1f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1