Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ef6508d1d719a07…

MALICIOUS

PDF

84.3 KB Created: 2021-09-16 17:36:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fd97cf0ea459f273799e983ed2b5cde8 SHA-1: 84d8fa630f0dbd1226f5eb7fef8b2af38361d803 SHA-256: 7ef6508d1d719a079cc1a972f673d6ca01e40bc1fa623d428ce823ce127ad5a4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, likely for SEO spam or to distribute further payloads. The PDF structure itself is not inherently malicious but serves as a vessel for these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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=an+introduction+to+statistical+learning+2nd+edition+pdf PDF link annotation
    • http://pazarziraat.com/userfiles/file/vukiweninutopalowim.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/74583308054.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/96brksonjmk85nfgqosep9kjg1/14549987696.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/27009504505.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210902093754.pdfIn PDF document text
    • https://investkwik.com/userfiles/file/xovemegajofejuf.pdfIn PDF document text
    • https://biographiewerkstatt-singer.de/userfiles/file/lugepofenetagijewowemana.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/572a0f5652ad9028ccc20756633bf120/4436084437.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/lagifuneg.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/voxokinalulo.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/84146884589.pdfIn PDF document text
    • https://interior-mark.com/ckfinder/userfiles/files/sazapuwusagavekusujepuno.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/8479831153.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/files/31819287981.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/46740514729.pdfIn PDF document text
    • http://olympicthesportshop.in/uploads/luvilalanoti.pdfIn PDF document text
    • http://it-hair.com/userfiles/75151024025.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/jexezebunosisozibogi.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613153d1bb141---borojagej.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/90609304695.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/jedorilupuperikawowag.pdfIn PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/77510870019.pdfIn PDF document text
    • http://soupworld.de/upload/file/zajamujazinozofez.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/dopazinewiparimunemiluxa.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfa2434839---nikesikekutirugukoz.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_off0000e1da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9EC 18256 bytes
SHA-256: c8332153d340869885a84c959953e79eed61c327fef36c29883bb82a0645ffbe
font_02_sfnt_off00012936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12936 10996 bytes
SHA-256: c4050b05a78cfcf89a18a56f38b2ce1c55f0ca7236bc7c2818148ebbea386ee0