Malicious PDF — malware analysis report

Static analysis result for SHA-256 1638d53abcfc56db…

MALICIOUS

PDF

69.8 KB Created: 2021-09-30 19:08:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e42683287121376d386248342ac71ac4 SHA-1: 2d78ef4be02685d1746c5269bae3f653e54ef95d SHA-256: 1638d53abcfc56dbfdf113c8a87a0a950f8598e37504e3fb8feaedcdbacb0cdc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm the malicious nature of the file, likely serving as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://archism.ru/uplcv?utm_term=android+net+http+requestqueue PDF link annotation
    • http://3q1p.com/upload/file/210921003810013377u9ga2rpj6to2.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/rifopozokiredez.pdfIn PDF document text
    • http://khyljg.com/uploadfiles/files/8520956369.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/nedewamutuzugofibir.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/54733625604.pdfIn PDF document text
    • http://askaudit.ru/price/87558128634.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/fb0422d107d3c9bd3f5be95b396273a0/zebogopivepo.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/timakonegusaxajap.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/tixefiparudoruwuwefuzeda.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/lolimabutir.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/wuromo.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/55621003612.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/da5bpiu2fcp0e49u10qkr2vgaf/jodogumorugamujonosasekug.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/c3dc700630857956ef608edebb669fe5/53946930579.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16150dc3428286---rogetufekegekorokeziz.pdfIn PDF document text
    • https://n-v-v.dk/userfiles/file/wudibigupemimeselasedolu.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/59545410326.pdfIn PDF document text
    • http://bridgestone-ice-cruiser-7000.ru/ckfinder/userfiles/files/98939031497.pdfIn PDF document text
    • http://rund-sro.cz/UserFiles/File/19115979006.pdfIn PDF document text
    • https://nppmaudaha.in/ckfinder/userfiles/files/xexatifi.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/49308233292.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/85244270245.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_off0000b04d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB04D 15644 bytes
SHA-256: 7323e9a6f47ecd418de34d7e266fe1fc6a0a31f6613ea9ecf725e192aa07aea8
font_01_sfnt_off0000d853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD853 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f06a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF06A 10508 bytes
SHA-256: d07da40afd83e440ba25d9d069f9a13c2ddd76f9f53534557956b2a57cbf7950