Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d81ab1f1fd4cf69…

MALICIOUS

PDF

86.0 KB Created: 2021-06-27 04:13:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 4c5c8a0a1a024f20a91c2f96c1b8f0a6 SHA-1: f712920b338fd842682a40da85d632cc0329ecea SHA-256: 8d81ab1f1fd4cf6988786a1604ab3c76e7933708d77a8b78d2e26a51eac88ad6
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting. These links likely serve to redirect users to malicious or phishing content, a common tactic for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://moestuinwebshop.nl/userfiles/file/xenes.pdf In PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a8a534f37---wapebop.pdfIn PDF document text
    • http://pelesiuvalymas.lt/i/File/66368321282.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/e70f0e46498bd07bee176cecccf44c98/fukusukawigewugod.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/kebexaruvowozefuka.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb266928899---83054782324.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/quu6oedimlabqtp8d3rrf3jskb/42827389200.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/276023bb68e7a7ddb71c756180f9e517/28283088517.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/36328521374.pdfIn PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/fa6b6a43d138c9c4e2bd74843dcdaea7/73046863938.pdfIn PDF document text
    • https://webtechnocrats.com/upload/file/gezetavelorijivom.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/vuzirubemaxuraxufimuze.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/nokusuki.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/rstuaq1k8vieedjg09s4obo2qn/jisolufowitevusavaz.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/zujupisopejurove.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/574andb4itaicbqib50jr0bpn2/83149536032.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609044a4701e2---segip.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160803b2c7d965---96835340635.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/b96155fc2ddd042f9c5f909e42e4f876/netazonifivakuziwi.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd1c9c82cb4---55694659827.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bf29ab433c6---rimonedafipiduf.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b927964b280---favatiwotames.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/10994ff9967597dcc4091d6c85c86835/13403756819.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/zituta.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/titolepilipoma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=numbers+1+to+10+gamePDF 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_off0000edc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000105d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D2 17044 bytes
SHA-256: 58f3b663fece0cae6bfcb614ec960d59a8b045541803e3738a87b0824e9e2453
font_02_sfnt_off00013286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13286 10600 bytes
SHA-256: 50512125e6b952b474e9ca2ee8501b9c475274540571d3b9f0b8db7ed7e18ca9