Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4a9fedfeb1e383…

MALICIOUS

PDF

90.5 KB Created: 2021-07-16 02:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1efdcd37cfc5206a9051ac8dca0d25ec SHA-1: 21bc68432cda981b2fa437c9c2334564de4cfb60 SHA-256: 8d4a9fedfeb1e3836794a92cd6cf3034f0e53f7218389409142520c8387aca73
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ClamAV and an ML classifier. It contains a link farm pointing to numerous compromised websites, likely serving as a distribution point for further malicious content or phishing attempts. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicate a deliberate effort to create a network of redirectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://stoewebdesign.no/userfiles/file/fibufebikalol.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/guzezosulato.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/be9f87c0ba61e3915371a8b2797a92d0/73981897532.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160c058475a1f4---6663463018.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/8f890d1557feaf50d07b86122de0a0f1/6738312435.pdf
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a8aa52d75---temegubobonawuxapovikuv.pdf
    • http://akcjonariusz.com/UserFiles/file/gajed.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b17c86c3a36---93823116331.pdf
    • http://podiummoda.ru/userfiles/file/48152106205.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a60932e33b7---52362976610.pdf
    • https://arab-hams.com/Ups/files/81402004595.pdf
    • http://hanasushi6.com/uploads/files/nuzakuvi.pdf
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0bed2bf21---nujexakanaxipovalen.pdf
    • https://aiaciran.org/cache/fck_files/file/daxobozexuju.pdf
    • http://akicgiyim.com/userfiles/file/nawapijujobugegok.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073c8dcb05a1---zikize.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608645b6aae59---58152545380.pdf
    • http://krevue.cz/UserFiles/File/resowixidosa.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab59fda61a0---bafimig.pdf
    • http://jagodkaprzedszkole.pl/userfiles/file/82885358899.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606e310fd27db---9669912806.pdf
    • http://steps4cancer.org/clients/a/a7/a78c374070a178914b502abaf3db82b8/File/65547002679.pdf
    • http://abimobiliare.pl/pliki/File/33420990778.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/80ec51074f7edfc61cf317c2f5d89f1a/86796037785.pdf
    • https://www.nexidia.it/wp-content/plugins/super-forms/uploads/php/files/b4f7c1ecd9caf03606decbafe8def1a5/jitalazajodelomusigifarin.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/f3928cf030a5f4a540078b424e7b054f/gupexogofoxatupovi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=is+an+afternoon+nap+good+for+you
    • 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_off0000ff2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF2B 16792 bytes
font_01_sfnt_off0001173d.bin
18e2f1815fb0a63819d859290dc4514820172e26479bd90b3d6a5c8005b1420c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1173D 16732 bytes
font_02_sfnt_off00014289.bin
17842feb557d823271d171488a946795231dd879c4710405290f9cbbeab87dd8
pdf-font-stream PDF embedded font (sfnt) at offset 0x14289 10700 bytes