Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b1c4d4a8fd851ee…

MALICIOUS

PDF

83.4 KB Created: 2021-09-18 01:02:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 14e1435109dc326f7b1807bb65f8012f SHA-1: 107f4c9b4611b9273c506ff505b7fbd14ab2288e SHA-256: 8b1c4d4a8fd851eeb4dff7555f33374e42fdb3e9b6e0b98f6aee4dcb17f30b0b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm for SEO manipulation or malicious redirection. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://splhardware.com/UploadFile/file/2021090613455273499.pdf In PDF document text
    • https://dakhoathienhoa.net/images/files/18120183963.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/lutuz.pdfIn PDF document text
    • http://bindashnews.com/userfiles/file/70812961230.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/serididarulumuxa.pdfIn PDF document text
    • http://techscreening.com/userfiles/files/39748728952.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/wiramolotufolodumi.pdfIn PDF document text
    • http://redeyeldn.com/userfiles/file/83788233795.pdfIn PDF document text
    • http://domingo.hu/ckfinder/userfiles/files/81219194235.pdfIn PDF document text
    • http://geteffective.biz/uploadfiles/file/welawigizakumedunaseji.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/60866697781.pdfIn PDF document text
    • http://xn--80aadcnaeutgftohcogh8i8dsc.xn--p1ai/pict/file/sugibiripojuxi.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16140bffaadd55---63103031468.pdfIn PDF document text
    • https://ksuskalology.com/images/file/92869945885.pdfIn PDF document text
    • https://maisonforville.be/documents/file/569967096.pdfIn PDF document text
    • http://kfbma.org/files/fck/file/jipanozosa.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/67667009158.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16140e9e9bde61---nopofotaduti.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/2afd660085d4e6f710466f80b4b4175c/todawedivolovamajovufe.pdfIn PDF document text
    • http://angelofthewinds.net/ckfinder/userfiles/files/74631931738.pdfIn PDF document text
    • http://only-svet.ru/upload/files/kowule.pdfIn PDF document text
    • https://ip-pharma.net/data/files/57489078486.pdfIn PDF document text
    • http://yjccnc.com/upload/files/1907195561.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/89540313431.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=mobile+framework+for+ios+and+androidPDF 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_off0000e2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F0 16996 bytes
SHA-256: e9557d30f22cb042a2a00e960da5e5b8135ca87409a9f64540a0a16cf85f03da
font_01_sfnt_off00010f3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3E 10728 bytes
SHA-256: caa6d9fc4116471428133b2cd023f906c9207c06274489f7492b7e300deb9c60
font_02_sfnt_off000127ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1