Malicious PDF — malware analysis report

Static analysis result for SHA-256 85cdc2fd5ae0fe7a…

MALICIOUS

PDF

81.6 KB Created: 2021-10-08 16:44:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 74d2b45dbe3d02f1fc6b89dd6e385f49 SHA-1: 48763d30ae56297a5da6266ea14a9fad4829ac36 SHA-256: 85cdc2fd5ae0fe7aab21a2adf01ed63889656e338a8660800281612ee7477cda
156 Risk Score

Malware Insights

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

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics strongly suggest this is a tactic to drive traffic to potentially malicious or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://terremeraude.com/userfiles/file/28661577342.pdf In PDF document text
    • http://tercovci.cz/files/file/ponupemababarutuxejuruvor.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/votononuvig.pdfIn PDF document text
    • http://hyundaiokla.com/uploads/files/xumunarolewapabusak.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161349a1d3ee0e---kebobapikibekuli.pdfIn PDF document text
    • https://ikorti-iao.com/userfiles/files/kovosofigesexenakoloburi.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614a110ee9e43---sapamewutomapijebol.pdfIn PDF document text
    • http://tichdiem.surecare.vn/uploads/userfiles/file/14014222203.pdfIn PDF document text
    • https://cryptobasics.biz/uploads/files/jefubogizelisukiwaserez.pdfIn PDF document text
    • http://shijijiaming.cn/filespath/files/20211002234652.pdfIn PDF document text
    • http://35ct1.com/images/ckImageFiles/files/27520536447.pdfIn PDF document text
    • https://theptaynam.vn/upload/files/pufizofugejok.pdfIn PDF document text
    • http://immobilieninvestors.net/userfiles/file/fukinititebaparenexo.pdfIn PDF document text
    • https://cowichanmusicfestival.com/userfiles/file/39565518270.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/50279891957.pdfIn PDF document text
    • https://hometutorsdelhi.com/userfiles/files/xabukimixusira.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/37733541686.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/22579844487.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/f09ef8fd329fa35b933ba9dc35122590/sowujunetejemi.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/bujegelupozomid.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/17337956321.pdfIn PDF document text
    • https://airbays.com/userfiles/file/puvoripimobuwufemowinagu.pdfIn PDF document text
    • https://apsco.ly/userfiles/files/53608995028.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=si+joint+pain+at+nightPDF 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_off0000dbb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CB 17992 bytes
SHA-256: 932a4a8d4ea8e849353ad1620da68808d6d13715f22cf5be8894476cf3c5b889
font_02_sfnt_off0001222a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222A 10292 bytes
SHA-256: ca3156b99881f9fe6f223dca079610ffd3ca0ff5bb814015c6ffcf6f9aa36466