Malicious PDF — malware analysis report

Static analysis result for SHA-256 45c26eb28ab46fc6…

MALICIOUS

PDF

83.2 KB Created: 2021-09-11 10:23:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 99fdeeb5060387a3b4889476e970d8eb SHA-1: 2c4b52353dae8e1bbc32f8ac6481e451b246e3bd SHA-256: 45c26eb28ab46fc6946fe609eff0e96ebe5b3bcbde4d0ca3d68b4b3bb60d6f67
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files, many hosted on compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to download further content, likely malicious. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://csc0532.com/userfiles/file/20210911002855_kzgy14.pdf In PDF document text
    • http://njchemland.com/upload/files/58459276068.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/90426314515.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/mfre2mof92g3qbv1n0isvf3lv8/68028230541.pdfIn PDF document text
    • https://feniks9.ru/ckfinder/userfiles/files/dopimupubikaburize.pdfIn PDF document text
    • http://iviltra.lt/images/files/94815012422.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/90673056527.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/femiboxetefekino.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/gemosuxapoduxi.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2b0396e75---mibagirupufoxap.pdfIn PDF document text
    • https://r4binsh4h9-att.com/contents/files/4230256690.pdfIn PDF document text
    • https://mr-alian.com/upload/ckfinder/files/dewofawazojexuzezagurise.pdfIn PDF document text
    • https://magnanerie-cazilhac.com/userfiles/file/zupanawomapazabafikog.pdfIn PDF document text
    • http://waxiangyuan.com/upload_fck/file/2021-9-4/20210904203450169097.pdfIn PDF document text
    • https://devcons.org/uploads/userfiles/files/zekogonowu.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210906092140.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/sogefudivimubumijisazu.pdfIn PDF document text
    • http://stepasidemedical.ie/images/uploads/file/sikitepofuponebo.pdfIn PDF document text
    • http://xingzhongjing.com/userfiles/file/20210904004701_1057975035.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/18512932374.pdfIn PDF document text
    • https://haidangpc.com/contents/files/89863600681.pdfIn PDF document text
    • http://pinedafoundation.org/imageuploads/file/56726509019.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613905ca23aed---fidosomagodomod.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8ce5b892c---wewasawi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=pubg+mobile+gun+gamePDF 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_off0000e3a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A5 17080 bytes
SHA-256: 6687d7b1a965ff04d62ae65043315113c8b025a0eb5a3e2481b8b82c9a09ec55
font_01_sfnt_off00010fd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FD5 10324 bytes
SHA-256: e48473b4e2e5fff2f76c7c61bc453bc2d1e8ef48553d041fab4e09ff75f61d1f
font_02_sfnt_off00012705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12705 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1