Malicious PDF — malware analysis report

Static analysis result for SHA-256 b566f79336f2968c…

MALICIOUS

PDF

69.6 KB Created: 2021-09-28 22:48:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dcc54417058a8b0e414e49425a8c854b SHA-1: 7fb219fb9eb8d35d5812a17505fe0545cc51bb2d SHA-256: b566f79336f2968ce0765dfdc97390097a5722b0824b0fe54f64ceda35580e0a
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS uploads and disposable domains. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute further malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://pistant.ru/uplcv?utm_term=elementary+linear+algebra+8th+edition+larson+solutions+manual+pdf PDF link annotation
    • https://barrierball.cl/ckfinder/userfiles/files/84652177146.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/6v0dv3npnto9s6hn7u40c1qetm/69594201301.pdfIn PDF document text
    • https://kor.mycultureis.com/FileData/ckfinder/files/20210927_BE83D54E588EFECF.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/629586ba8d8b819f60ae761cb1581ca1/gekajove.pdfIn PDF document text
    • http://christopherdallo.com/file/sanowekusotufet.pdfIn PDF document text
    • http://boxethai38.com/upload/file/94685378800.pdfIn PDF document text
    • http://vincitydata.com/uploads/ckfinder/files/42687861688.pdfIn PDF document text
    • https://10fci.org/userfiles/file/lusakikom.pdfIn PDF document text
    • http://lustigersteirer.at/userfiles/file/zubivexivovikukuwe.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/patewokix.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/xiwawibemawurewovetewuw.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/74961086313.pdfIn PDF document text
    • https://adesso-moosburg.de/images/file/wigolobegibofakexipedon.pdfIn PDF document text
    • http://josephfellerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bexuxejujusi.pdfIn PDF document text
    • https://weboonline.com/ckfinder/userfiles/files/69219395970.pdfIn PDF document text
    • http://jujucuisine.com/userfiles/file/lopeg.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/xaraludupexewimodojuwif.pdfIn PDF document text
    • http://lapmaymn.samdigroup.vn/app/webroot/upload/files/59885151533.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409006c15e8---sonimenuwosuzulisujusaza.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16140ac4561f8c---texudike.pdfIn PDF document text
    • https://lanegarrett.net/userfiles/file/lenajifusobibi.pdfIn PDF document text
    • http://otworz-biuro-podrozy.pl/userfiles/file/15390079527.pdfIn PDF document text
    • http://deaprogettazioni.it/userfiles/files/53838824402.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/28afe41931dcdd0ef329524adc66dc95/latedifurox.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109242329255723.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_off0000b153.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB153 11492 bytes
SHA-256: 5b50cb7bb35503ce55b5966d56f91280542cc66d9d576fefcaf50022d388980f
font_01_sfnt_off0000cbe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F9 14472 bytes
SHA-256: dcbcd01a4b4b44620facb51c58eeccd04ad711cd2008b56dedef810541f80bc1