Malicious PDF — malware analysis report

Static analysis result for SHA-256 e137c4f8fbbf1523…

MALICIOUS

PDF

94.7 KB Created: 2021-07-04 02:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: aebf4cea317a1c581bd1cf85f1818aa4 SHA-1: 54023f7ff2e86dc0acaaf9fcf287a2f1cba9a7b2 SHA-256: e137c4f8fbbf15233cd79b5734d1adcec5858a8a9c1ee611ce12d08fc9432b40
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is unreadable binary data, indicating it is not intended for direct user consumption but rather as a vehicle for these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://dobraukraina.org/sites/all/sites/dobraukraina.org/files/57328596713.pdf In PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/c6750fe60f20a167f022cd278cbd198e/18557806448.pdfIn PDF document text
    • http://kbchina.de/upload/mogaworage.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/9db1e6954e9c4e81fd274f205ba30558/zimikolorivuzoleka.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/l6ofgpcnov875sun911164hp0k/70947078491.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/1062697275.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609ea11aef545---nufubinovapax.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bff61e7cd5d---zawodumakudugixizutot.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/d055307c222d4462f41fcf43d4828c27/43707211402.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c407e5789---fokusinodopurafemu.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/nco455caa98709oseim6rtalr2/69709946372.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/r1ffra1090aahu6ofkrq21o2h1/paxosozuseduje.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a708d110d9e---5792453229.pdfIn PDF document text
    • https://kede.org/userfiles/file/22344463003.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/54737265026.pdfIn PDF document text
    • https://rzfmuhasebe.com/userfiles/file/37894407822.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c744998b6b6---20392166416.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c70feb003a0---rekolojatamijedubufuzuxo.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/bisalitupegobi.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/cft2qkm167mi3sf4n5rh3m97ve/56954002643.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/49372019022.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160afdb3a0a187---xazefigajogiremof.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/15403466228.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/68130727760.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c29e988f9e7---subupoxivokajawewotu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=sudden+ringing+in+one+ear+spiritualPDF 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_off00011139.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11139 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001294b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1294B 16772 bytes
SHA-256: 4066baf5d01aae77cbdf7a12436184577426d92f0ed94f3aaa88940aa802c1f3
font_02_sfnt_off000154e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154E7 10744 bytes
SHA-256: 4cfde6252ff9fc98c53104fcc2f6298a00c99aeb5890c0d9ee8be46ab5e91a1a