Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f1a3cdc38035634…

MALICIOUS

PDF

69.0 KB Created: 2021-06-12 09:04:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 7a402c9d71be70cce7518ac934ee502c SHA-1: 0a7a8f69614deceef250144648a1b10af646a1b9 SHA-256: 7f1a3cdc380356349b160040e300c29bd31eb14ec58934c0c512b007b90b4378
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document is identified as malicious by an ML classifier and contains numerous embedded links. These links point to compromised WordPress sites and other domains, suggesting a phishing or malware distribution scheme. The document's content, though heavily obfuscated, appears to be a lure related to 'overtime pay worksheet pdf'. The presence of multiple links to compromised CMS upload directories indicates an attempt to host and distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://allytemp.ru/uplcv?utm_term=overtime+pay+worksheet+pdf PDF link annotation
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b01083c1a5f---giwujomuralejepam.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/5ff32b1af78d6738f994994c3c3456c6/pixekavikomelejuwe.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/9c6f2c9c2eb0ee51c69af630061dc90c/364210564.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160780c6bd75c9---revorugidotafelitanogomed.pdfIn PDF document text
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/21c84900bfe69b71f224dcd88df6dd5c/merikisogogisilebopa.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/281904481349.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/61560fc5ad8dabb2ae45fcf0a6ceb515/82611930415.pdfIn PDF document text
    • http://cloverpark1959.com/clients/51168/File/17086901399.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b993bfd5557---35898259395.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/6ckoo6a2kgef8h4l8va5k2r3l3/57444270860.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608828cd989ec---vesufuwezifunefi.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a92631b2a91---42120660571.pdfIn PDF document text
    • http://aplus.to/userfiles/file/25464413518.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/87894756921.pdfIn PDF document text
    • https://zegabilisim.com/calisma2/files/uploads/mibazo.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/4onedduaj87l0qaasibpmonqhk/kejidizazazep.pdfIn PDF document text
    • http://domeinbeverdonk.be/assets/files/file/64690249737.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF9 5596 bytes
SHA-256: c9ee44c6727ae9eea09797542b6173b4807b1bf65d26148d0d13b236ce328f34
font_01_sfnt_off0000e2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2EF 10688 bytes
SHA-256: d816bef165a84efe33ec3252762eee5b355c13a835ae2f55b2d53196bf7f3573