Malicious PDF — malware analysis report

Static analysis result for SHA-256 135e721dd42ce3d5…

MALICIOUS

PDF

73.3 KB Created: 2021-09-24 18:29:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 73a09dbf8732b15e849d9d63ed8e47e6 SHA-1: 8d876cc2f4740cd2fc71feb0568faa81bc08b840 SHA-256: 135e721dd42ce3d5e234913946b7670e2ffd8a8b57b81abb3ff66ebf0adeadc1
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. This suggests the primary purpose is to redirect users to a network of sites, likely for SEO poisoning or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://azco.friend-match.com/upload/files/96610223995.pdf In PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/doxulomi.pdfIn PDF document text
    • http://nhatrangpalacehotel.com/app/webroot/upload/files/72252406976.pdfIn PDF document text
    • http://piotrkowska77.pl/zdjeciafile/88679114240.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20210902033102.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/12029657416.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/51543661988.pdfIn PDF document text
    • http://laxycoffee.com/upload/files/benozibeviwebefo.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/4126446840.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/19012466557.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/44716827960.pdfIn PDF document text
    • http://aroma-es.site/yamituki-n/uploads/files/26228815064.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/jiput.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614d5eaeeb9d4---29091399.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/59ff4ef75bc0ab8da83662699772f62f/2333695649.pdfIn PDF document text
    • https://www.temtechnologies.fr/ckfinder/userfiles/files/poperiwudotebapuweravede.pdfIn PDF document text
    • http://dochoiotovn.com/uploads/userfiles/file/jijipixomifa.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/jomifegagegizanakarerok.pdfIn PDF document text
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/30750196276.pdfIn PDF document text
    • http://lachambredechos.com/userfiles/file/25966167957.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/49032830774.pdfIn PDF document text
    • http://www.kevimotor-rock.hu/files/files/82033437150.pdfIn PDF document text
    • https://dehayemek.net/upload/ckfinder/files/negidijolalu.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/71896311241.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=debug+ios+react+nativePDF 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_off0000b6dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6DC 18644 bytes
SHA-256: 3209e2d0205ad67f12b35aa1e44408c0955dbd2d9f7b06d8f8f896f01e9f8879
font_01_sfnt_off0000e6db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fef2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF2 10668 bytes
SHA-256: 60200c1a23edfacb9e0cfedea452cb8cdb4c9d4a10f34b75808e434dd82c1581