Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6ade0a0ef2e0d04…

MALICIOUS

PDF

85.0 KB Created: 2021-06-27 01:09:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1592d78467121ca4cda6d9aad57671d SHA-1: a52e46c2c5073dffb112ff8f18bc3a0775263713 SHA-256: c6ade0a0ef2e0d04f4e07fa813e7dff3f1255d7a6fbd8411f08627a2ef6891f0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and potentially malicious URLs like https://coretry.ru/uplcv. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://coretry.ru/uplcv?utm_term=semi+structured+focus+group
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b5550f5aa18---67912329950.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/fgkjic1iegn7j6bvk70tnuqmke/womuparavofedovizuti.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bccf5994276---pejovewo.pdf
    • http://aircond.md/upload_fck/file/tomozigafajafu.pdf
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607774784dc5d---80952267736.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160cf8a0c6fd95---zeravirobevaxafuzosa.pdf
    • https://alihuata.com/userfiles/file/zitom.pdf
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/gavijiborixuz.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b041f96371---58340368471.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/abielumrd9m8m7l23d6jcb32iq/kesuzimozovoxotifinef.pdf
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/waweduloj.pdf
    • http://quangcaosms.org/media/ftp/file/20650929912.pdf
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a59b5c97a51---xawedinixim.pdf
    • http://soluzionebenessere.eu/userfiles/files/bivuvovivavarokezid.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d0f6d6fae---57579954848.pdf
    • http://urbanconstructions.org/images/uploadedimages/file/leleruronipodaxabivep.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ffmhp73vqc9vgtdscbqc2a7e84/13668144682.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/a53be8fad7b34e8a496fb80a12e9ec2a/jozufidomu.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160720a7b584af---34489142123.pdf
    • https://peterdegendt.be/file/41908580080.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1608348c1e0fc2---tuvumufekupekezawabuzemu.pdf
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/f5svqjh5pkco3kjj5t04jg77as/77574852059.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609a98afd13e0---198429453.pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb07.bin
e57a2c93eb837a92205ed605810ab9ceb036019d0a2c4f8386ae07b54e69ac9b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB07 16748 bytes
font_01_sfnt_off0001161f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1161F 16792 bytes
font_02_sfnt_off00012e36.bin
d315e1e4e0ca22d0287a1a8fb09c4d151413dc93b47f8a1be11925bb49fc96c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E36 10828 bytes