Malicious PDF — malware analysis report

Static analysis result for SHA-256 4579d5b8a97b6a77…

MALICIOUS

PDF

102.6 KB Created: 2021-09-15 10:02:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b4c58d07d7615604b882b993bef92ea3 SHA-1: 6563e33ca16e62c254baacd2c45f7be8c1b3f0d8 SHA-256: 4579d5b8a97b6a7797aeca40823483b524550c81388f5526d716d5dbb1c563af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites. The presence of numerous PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings strongly suggests an attempt to distribute malicious content or phish credentials through these linked sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://ayrh.internet-match.com/upload/files/dijidowixu.pdf In PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/84836917522.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee00ddfe5e---lizudexopemobagixulixop.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/bc1b41b1d498f4b4888e2a008898321d/jivifemagipudopobasozinut.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/24365927254.pdfIn PDF document text
    • https://szallas-karpatalja.com/upload/15334710044.pdfIn PDF document text
    • https://costarica4d.com/contents/files/35809546806.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210914185430_8tbusn.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614193e27d91e---morunegagekofiruz.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16131b0383d825---fakijudotogutes.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134af00797e9---4306667217.pdfIn PDF document text
    • http://heizler.hu/files/file/31283711779.pdfIn PDF document text
    • http://csp.hu/editor_up/ladakadijaxivejiri.pdfIn PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/xilemolanunoxar.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb362855c1---vonajituferefikivexabiv.pdfIn PDF document text
    • http://geo-equipe.it/userfiles/files/fedugalopedanirezudakogo.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/eilq7caos4eup56pmsulj7rmbl/10573572231.pdfIn PDF document text
    • http://villaroyalenews.com/userimages/gopuvufam.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/c24acabaa892644bf435fc989e53b9d2/litivexik.pdfIn PDF document text
    • http://naphotelbangkok.com/userfiles/files/70149105188.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/34732940928.pdfIn PDF document text
    • http://trunglam.vn/uploads/userfiles/file/baburakagatisojuk.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/bodenoxoli.pdfIn PDF document text
    • http://iktoktatas.hu/files/file/nutidarunirosivobes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=jack+ryan+season+1+full+episodesPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012a69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014280.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14280 10864 bytes
SHA-256: 4c10ce0c6c5c761057c7b3244db6bac034f0fdc1f44417f1db2f3e24e231d409
font_02_sfnt_off00015bc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BC9 18948 bytes
SHA-256: de2586b0982d8da089a0a26b1fad84db55e8b080f945f5f81030bf3320c19930