Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cb6c80404099483…

MALICIOUS

PDF

80.0 KB Created: 2021-09-21 05:55:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8dcc5b93f93bb20e53d4c44f428a128d SHA-1: c815b4f203db4b63ca6567a64f3f9e2b4657fd67 SHA-256: 4cb6c80404099483d667c2761a8b4f4b23d9a665da5d67d13eb10bd4ee3bb53e
164 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content to infer a specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://medizator.ru/ckfinder/userfiles/files/86065864087.pdf
    • https://eco-translation.ca/upload/editor/file/mupepulolelilot.pdf
    • https://maffart-guy.com/userfiles/file/lukaloxebov.pdf
    • http://salsainkonstanz.de/media/files/95511107903.pdf
    • https://xn--fiqa735be48e.com/upload/files/bimivexexatogal.pdf
    • http://tscyw.net/userfiles/file/20210908165610_sifbla.pdf
    • http://avision-italia.com/userfiles/files/31221468722.pdf
    • http://sakuragiramenandsushi.com/uploads/files/61557179258.pdf
    • http://bakefruit.com/uploads/files/202109061702401734.pdf
    • http://pomocnaukowa.net/Upload/file/wewugazajuxuxata.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612f500a378d0---50371904539.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c918550a7d---83257910676.pdf
    • https://apexsafetyproducts.com/ckfinder/userfiles/files/menupozet.pdf
    • https://ssvacancy.com/ckfinder/userfiles/files/38855258743.pdf
    • https://corcreation.twbiz.me/data/fckeditor/files/20210919_015828.pdf
    • https://ahirealty.in/admin/userfiles/files/daneserumefalabapevanatov.pdf
    • http://lehnerkom.de/images/uploaded/file/79582000176.pdf
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da8132c2d5---35207511565.pdf
    • http://vhktn.at/images/content/files/zobuwoges.pdf
    • https://auto826.vnpec.xyz/uploads/files/gajikidu.pdf
    • http://torremaggiore.sitmap.it/files/files/32833783537.pdf
    • http://hasdeu.md/data/userfiles/files/puweliwovobemi.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/161396808277c8---kovujegovamubobogojafiko.pdf
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141b33edb024---90700299142.pdf
    • http://aloeverajuice.cz/files/file/20227565349.pdf
    • http://hiredriver.com/uploads/assets/files/pifuwu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=play+genshin+impact+android+with+controller
    • 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_off0000cf5e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5E 16792 bytes
font_01_sfnt_off0000e770.bin
fdf310d447bb647740c2c2c0b01c1184215f2dbb244032824136d6c4a6990da9
pdf-font-stream PDF embedded font (sfnt) at offset 0xE770 18704 bytes
font_02_sfnt_off0001188d.bin
4c3ef65a4c7e9bc31e3aa169ce2125f9680fa748225355fa5ff4c8a37c422adb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1188D 11164 bytes