Malicious PDF — malware analysis report

Static analysis result for SHA-256 803834c3bd47420e…

MALICIOUS

PDF

98.0 KB Created: 2021-08-26 06:20:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-22
MD5: 239a4829859ba7a7e17ba0880e8c422e SHA-1: ea258c5a9e3adb146cb2f2e2ee54e89f74434287 SHA-256: 803834c3bd47420ec028592b092a209dba0834924947da1598e8c2a0866eb9f2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://itandem.net/ckfinder/userfiles/files/zunokiler.pdf In PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/21863520263.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e8f7eef81---91698431363.pdfIn PDF document text
    • https://uniqrelation.com/userfiles/file/65539662698.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/10e9134bb39de44deea2e013a045ebf5/56270300494.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/f8409869d8d51635cafa27620d3e5bcb/79886359872.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4f04d7fbb---titewafupagifo.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/62825039010.pdfIn PDF document text
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/aaa9ec1c18961a667417eb46679a712a/tizurojiwelibenakutuwa.pdfIn PDF document text
    • http://erbaytag.com/resimler/files/3456020939.pdfIn PDF document text
    • http://industrialdevices.in/uploads/81339068202.pdfIn PDF document text
    • http://www.neocota.com/fckimages/file/mufipo.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/41390204840.pdfIn PDF document text
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5cb1176fa---neledosijobasep.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/sinugexuguluxurarilix.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1658faf3ab---52489330788.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/dizibavusilipiwabivadoz.pdfIn PDF document text
    • http://allivecoat.com/userData/board/file/54391040369.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/141310224810.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/bugusexezokovidimimejexol.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210824_31D18360C5D5B293.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610314ce7d271---34008320344.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606d581097745---mesox.pdfIn PDF document text
    • http://yngc.ru/admin/ckfinder/userfiles/files/76798881888.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=mouth+drooling+meaningPDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_008_off00015c3b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x15C3B 18328 bytes
SHA-256: d9f5e66163d907df9b2c2f031b8906ab183602eda4757f3e8ef428a9cf922d60
font_00_sfnt_off0000e7dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7DD 22340 bytes
SHA-256: d4d4200c43b2c589fa4db67123ce2c2ecc62813f89fc8490a009483bc9c8233c
font_01_sfnt_off00011eda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136F1 10620 bytes
SHA-256: 7e74107c84ffdacbdf7b7500e72b1fee41055e6cc3c8827d3f4f00a7fb02502a
font_03_sfnt_off00014ec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EC1 3464 bytes
SHA-256: a8161c2f5ba9235eb51b4fcc43b6bb219725019365cb8d38f9ec25dfe5ce54ff