Malicious PDF — malware analysis report

Static analysis result for SHA-256 b56851d3d73ae78b…

MALICIOUS

PDF

81.0 KB Created: 2021-09-15 19:16:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c4ccc65bbfab3e4f946dbcf1b76d61c7 SHA-1: 546a990d9a81ef09e588daa10ac427cc2d720100 SHA-256: b56851d3d73ae78bd5ea24a1b615ef8e9dea98b77a41df44fce09f9a5ad6645e
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, indicating a link farm strategy. The ML classifier strongly flagged this PDF as malicious. The presence of these links suggests the document's primary purpose is to redirect users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://catamma.ru/uplcv?utm_term=how+to+make+text+size+bigger+on+android PDF link annotation
    • http://xn--tnqz8hz5cb8l.com/upload/files/gedepolex.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/wedijuv.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/rokosovikawedefu.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/filerapapawu.pdfIn PDF document text
    • http://theartofdesign.nl/ckfinder/userfiles/files/ziwanatavegewomodarugu.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210912183108.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d28c0b3631---80047482854.pdfIn PDF document text
    • https://marathonlaval.com/userfiles/files/26402527725.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/69690289379.pdfIn PDF document text
    • https://netiko.ge/img/Data/file/rimajoxipaxugileboteva.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/4423377222.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/girinexebonujokofeser.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/nugipalurawamefina.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/fibed.pdfIn PDF document text
    • http://bartuceviri.com/userfiles/file/gaganaduferagat.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348da29a4e6---nisedesaruvigowodupar.pdfIn PDF document text
    • http://sperrincaravans.com/images/file/lawok.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210904172303100.pdfIn PDF document text
    • http://rydelko.pl/userfiles/file/5959345261.pdfIn PDF document text
    • http://alwaysshine.com/fileimage/file/baxokigivewe.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372b6b86dbd---52772538594.pdfIn PDF document text
    • https://zapcdn.space/web/img/podborky/files/21762504492.pdfIn PDF document text
    • http://lehnerkom.de/images/uploaded/file/14494690333.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/79957329680.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/zofevom.pdfIn PDF document text
    • 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_off0000d5a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A9 11016 bytes
SHA-256: 3fbc8cee0684e8cadcd0a8d64bf7414bb7083f035114e67a4376e74460e80707
font_01_sfnt_off0000ef24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF24 18168 bytes
SHA-256: 0301bf5cf8d9628b4c619fec25c0f29936aaf8355b341b6019e1d1378913c5ea
font_02_sfnt_off00011e59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E59 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1