Malicious PDF — malware analysis report

Static analysis result for SHA-256 8efc139dbd5660a0…

MALICIOUS

PDF

142.8 KB Created: 2021-07-02 21:42:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d2926501cb30a23583b2cff1ebecd688 SHA-1: 320031b617d32bda34f5f1510d84477aea5ef00a SHA-256: 8efc139dbd5660a0c3c8c323c6d4824a2c92cf1b2c521622597e6feb553cb643
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress sites, likely serving as a lure for users to download further malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate attempt to obscure the final malicious destination through a network of compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9761

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://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/5eeb9de0c572065226107745d362b066/xijefuwo.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/350eba36347ae63b791608d9153b6abe/kumejafilomevifete.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/4feac3b9aa796a822fa6865e7493b849/42554606866.pdf
    • https://cardion.dk/gfx/fckimages/file/86034992873.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a461525f2b6---susuritiretixav.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/6fce53507ff144021e3aefefbb75a014/valunopugi.pdf
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16075af4c3e9f8---gopodadesajitet.pdf
    • https://samoinstitute.mn/uploads/assets/file/97214057512.pdf
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/7d76qohfd9mqn655enje5ag28n/temewagebitofi.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070c5c329e54---33036490283.pdf
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/6a12681bdfb3a9ae73808c71f87fa00c/38088533637.pdf
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/cca0197fa9dada9e142132a64e0f3cf8/73769324871.pdf
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/61918760501.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/466b56eb9a0afa2711a2bad466297221/88401356885.pdf
    • http://aimic.com/userfiles/file/87754029187.pdf
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/lf9ks4di4chomg9k0os7npqc76/69239740462.pdf
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/461aa55c8f64ed9873369b3b7d97aa49/wawefevanasenoropewize.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aeb0ed6976e---64080403184.pdf
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/ee6e036095c11db8d74142ba56eca350/1975429650.pdf
    • http://kyanite.tv/userfiles/file/vejajur.pdf
    • http://elsekmont.eu/userfiles/file/96064438904.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d70c72ba9b---fugiribugixez.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcbe2e8ab8d---novogujukurovoluje.pdf
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5a1b97029---75318326285.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/24c4e71d435c97075cea06bc6ec09053/mufejelilabezufoteb.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089396102959---zifuzijamakutasekofej.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=bologna+middle+ages
    • 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_off0001c73c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1C73C 16792 bytes
font_01_sfnt_off0001df4e.bin
9b2a973a036505cda448905592156c5df32d8d65cd281a01c935d19de7ca4ae3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1DF4E 21068 bytes
font_02_sfnt_off0002160e.bin
d7c6e7ed0b505d2424155b409d19354946dbde95b4205fa9911097823d219a38
pdf-font-stream PDF embedded font (sfnt) at offset 0x2160E 10444 bytes