Malicious PDF — malware analysis report

Static analysis result for SHA-256 48b0cc8ab6b7c7a9…

MALICIOUS

PDF

70.3 KB Created: 2021-09-26 21:54:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bc55d2246cbca213199c275481a71c32 SHA-1: 1d47c5e7471be88a928a578a2d2498ef5dca9c37 SHA-256: 48b0cc8ab6b7c7a932f79465dc6788eda0a21e330225394f2bd39be989f468ef
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It functions as a link farm, containing numerous URLs that point to other PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The primary purpose seems to be directing users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://renhedc.com/uploads/files/202109220811159700.pdf
    • http://asustainable.com/global/file/wukiz.pdf
    • http://xdankfort.com/rhnew/file/90055666244.pdf
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/c8b8i30n1m3jfe4t14jh4kr36e/42286502768.pdf
    • http://rococosofa.com/files/files/dofamesuremuzukew.pdf
    • http://chi-kara.net/Upload/files/83163077355.pdf
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/kutagerameraravava.pdf
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/40689b23f58cc298b8e4542e9c319c4b/65887949176.pdf
    • https://sheenabusesandcoaches.com/userfiles/file/kikagi.pdf
    • http://seyrimerdin.com/userfiles/file/vovasojanede.pdf
    • https://resortweeks.pro/userfiles/file/40253085780.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c098f68afd---gerem.pdf
    • http://phannhan.vn/files/usersfiles/files/74081044133.pdf
    • http://maybaobidinhdinh.com/upload/files/32938279897.pdf
    • http://royalgroup.at/tmp/dodusaferopamam.pdf
    • http://annassteen.com/ckfinder/userfiles/files/84923593215.pdf
    • https://lmbri.com/WYSIWYGImage/file/18566801007.pdf
    • http://salman-is.com/userfiles/file/77145559083.pdf
    • https://guapa2.com/admin/fck/file/vikiramukojew.pdf
    • http://momsystem.ru/public/file/85918605809.pdf
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/50294332841.pdf
    • http://gpe-el.pro/ckfinder/userfiles/files/gusudituwuvujanemikanesu.pdf
    • http://jungvassar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55318194660.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614b72871e970---92417867785.pdf
    • http://pijntherapie.be/uploads/files/93312328767.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=deleting+web+history+on+android
    • 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_off0000b280.bin
8df3fda647b44916f4022a4fbf711914ee3d7a1e7d203819cd8e8accd82b944e
pdf-font-stream PDF embedded font (sfnt) at offset 0xB280 10868 bytes
font_01_sfnt_off0000cb6a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB6A 16792 bytes
font_02_sfnt_off0000e37c.bin
aba27c4427d9e0ce4c870e90e092192ae0423cd99d46d635c2bef048bef019e3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE37C 15272 bytes