Malicious PDF — malware analysis report

Static analysis result for SHA-256 274756b4266996aa…

MALICIOUS

PDF

74.3 KB Created: 2021-09-03 21:03:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5a4221f7d63f46f16361c1600e319b2f SHA-1: dff772be9e3c80f534a084bbb2eb28c7a8f2e5e6 SHA-256: 274756b4266996aa22fc6ead44e1ae0abcbc6aa977e095827aea972b6740b95b
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to other PDF documents, many hosted on potentially compromised websites. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, but the overall pattern of linking to external files is suspicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://kominove-centrum.cz/media/files/file/37885723789.pdf In PDF document text
    • https://ctners.com/ckfinder/userfiles/files/81575412904.pdfIn PDF document text
    • http://amandamaitland.com/images/file/50909872128.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160825a47b6835---pofoman.pdfIn PDF document text
    • http://liyangah.com/Upload/file/gatuwi.pdfIn PDF document text
    • http://basse-normandie.annuaire-regional.com/ckfinder/userfiles/files/ravosetad.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160766fbdc6833---46910751083.pdfIn PDF document text
    • http://ihdbd.org/upload/files/41837044896.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/zomaxuzekawawafidofero.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/jenopuwi.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/bebvprnrvnf0jm8b13q8vk2r8s/wavelirexu.pdfIn PDF document text
    • http://skyrybupaslaugos.lt/uploads/files/2943174771.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/42f14fa83eb9122c9cf0ce979fe384a5/domadaw.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607f00b4b0b7b---33880040173.pdfIn PDF document text
    • https://taxiparga.com/wp-content/plugins/super-forms/uploads/php/files/da4d3a6220ef5ca27c4d8c130e2ffa3a/mokadisanuxupufuxegutupu.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/f88c5bdc09451f51a6a55c31a5cc9f74/vivobofubupozofikune.pdfIn PDF document text
    • http://tutek.eu/userfiles/file/pivaxafoxefamibi.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/dd50f66dacddbf49ad8cbb59618e8ea5/50818028420.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4d4bc2600---guwad.pdfIn PDF document text
    • http://easyhypermarket.com/userfiles/file/ziridamikef.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/dca761252fe7b42219422558090f1808/wujegax.pdfIn PDF document text
    • http://packamate.com/userfiles/jejefobeferel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=othello+pdf+act+3+scene+3PDF 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_off0000c0cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E2 10724 bytes
SHA-256: c13ceb3d3db5375b354c1f34392616fb1650befdd19d5112441319a580e90eb8
font_02_sfnt_off0000f18e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18E 16488 bytes
SHA-256: 8cd74de9de2c2362b700782215eeba8799aa900ccf8f6688842967b133c526af