Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d92bedc90cc3d2…

MALICIOUS

PDF

74.6 KB Created: 2021-10-10 05:11:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 497ac7ceeb034c1347b5004e486cb39f SHA-1: e9b7157157300f0bab2df531a8b42712c29a085d SHA-256: 91d92bedc90cc3d2b5a0a220ff6b887bca4e9ff6151a7d3d145c171cb2099fb2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were directly extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://medvor.ru/uplcv?utm_term=what+is+strategic+management+process+pdf PDF link annotation
    • http://risorsaterra.it/userfiles/files/dinilikigef.pdfIn PDF document text
    • http://circolosilverblufitnessclub.eu/userfiles/files/21853793749.pdfIn PDF document text
    • https://yennenga.org/business_school/uploads/file/butufatotuda.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/fizavu.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/20929188856.pdfIn PDF document text
    • http://columb-sklep.pl/userfiles/file/42003481117.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161492f617ee68---65502543578.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/15596094452.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/29799982619.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/36025765328.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/84e0a950b3d39798f0714e9eda1b9aea/kidufasadalifajuferomaze.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/97493301382.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/5003a9899f0002986a076a87dad76f5a/47214485609.pdfIn PDF document text
    • https://mu3yc792xh-rl1.com/contents/files/zanusifujozubotituzefav.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/47859216111.pdfIn PDF document text
    • http://abbuffalowings.com/uploads/files/silawujuf.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/211001034546866497exkvyr.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109260000145466.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/rapiv.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/f04fbd518df74f8c32255ec465e24c2a/dokojezasemedu.pdfIn PDF document text
    • http://greenld.com/userfiles/70828747869.pdfIn PDF document text
    • https://ghnservizi.com/file/kotujojijagesexu.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091415113286.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_off0000c1e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1E0 16060 bytes
SHA-256: 1c0f711d75e52164c521f653896540cf2c7138cf2a17ffc21ad2a0ec8079f4d7
font_01_sfnt_off0000eb0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0A 11016 bytes
SHA-256: e9df4ced9288c54240858b8f475f35920a8b0f7247c3fb5a1d3083a19c8dd795
font_02_sfnt_off0001044c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1