Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dba4de9aac5283…

MALICIOUS

PDF

81.2 KB Created: 2021-09-18 02:30:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 67f8c8bb0b26976ca84c924dd18c24dc SHA-1: 218866c8f996c2df5bd17bc1ee137339dbed6617 SHA-256: 81dba4de9aac528321ed778633140923159e61fbd89713ff1116a853e3d19dc2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or link farms, suggesting a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the embedded links and the heuristic firings point towards a phishing or malicious content delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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 http://www.alexgis.com/siteuploads/editorimg/file/42105996230.pdf
    • https://tour-paris-guide.com/cite_imgs/file/tudejetevokari.pdf
    • https://endeligmandag.no/e-brev/data/div/jusewalawedipilug.pdf
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/vulokazedum.pdf
    • http://mtjjt.com/2013/upload/article/files/210916084803744172irylh.pdf
    • http://iseveranscopy.com/upload/editor/file/69147126840.pdf
    • https://jjpremiers.com/files/1050390582.pdf
    • http://lukinserv.hu/file/81564062466.pdf
    • http://www.santamyoga.be/images/file/6790808644.pdf
    • http://ukwoodrecycling.com/userfiles/files/83768151845.pdf
    • http://bfr-bialapodlaska.pl/userfiles/file/4603143762.pdf
    • http://mybed.tw/uploads/files/202109121143262633.pdf
    • https://inprovitecuador.com/ckfinder/userfiles/files/supivukojiloronadosi.pdf
    • http://xn--42cfa4ewb0a0b3fwh.com/imageupload/files/ledinexezerebu.pdf
    • http://usateatop.com/_upload/files/4417768702.pdf
    • http://huijingweb.com/upload_fck/file/2021-9-12/20210912225700796564.pdf
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/vnt32vs0qc5krn4s6mrc92beq3/93282431039.pdf
    • http://togclick.com/media/userFckfiles/file/vimalefexumafadoxegug.pdf
    • https://komunalno.vrgorac.hr/files/64388386310.pdf
    • https://birutelorasin.com/contents/files/72539392620.pdf
    • http://olimpic.hu/ckfinder/userfiles/files/delidiwixo.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4661e5955---xitidofowekefa.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/be3e5547cb629724b8ff3d03b74c8826/kumuxelatus.pdf
    • https://optimumquestsolutions.com/ckfinder/userfiles/files/81233896218.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=dbz+gba+games
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000be39.bin
d55396eec11d1778a763452cf83e9ab22bdd27af4124ff85fca48fa50889b57c
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE39 10092 bytes
font_01_sfnt_off0000d4cb.bin
9aa10fb238227a0bb08feb21e3e74ab540c935162a6d8b6a92247c4a3a827585
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CB 18096 bytes
font_02_sfnt_off0001035b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1035B 16792 bytes
font_03_sfnt_off00011b6c.bin
438f0c910b05e397bbba698da855102805ba5f68da0831b5e6a9970d8ab40c79
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B6C 17820 bytes