Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc77e11d51d66234…

MALICIOUS

PDF

85.7 KB Created: 2021-09-15 01:19:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 79c4ec16742981d3c6cc7332680a945b SHA-1: 50899053e68c875463f9043d0d72fb468d13de18 SHA-256: bc77e11d51d6623407c3e975709ef5adda8f5dc484d4bb710b56deb2017d6019
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to compromised CMS uploads and disposable hosting, likely to distribute further payloads. The presence of a 'download button' lure further supports a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141134711681---rifarelafu.pdf In PDF document text
    • https://www.auto-ecole-rive-droite.fr/ckfinder/userfiles/files/58480259063.pdfIn PDF document text
    • http://prestopc.it/upload/file/jowatapumixivim.pdfIn PDF document text
    • http://sozopolihills.com/userfiles/file/xotamekeropuwepawafifudix.pdfIn PDF document text
    • http://futsalcb.cz/picture/vtextu/file/dimelumoxivokesel.pdfIn PDF document text
    • http://dajuicebarus.com/uploads/files/84938674924.pdfIn PDF document text
    • http://tchid.net/userfiles/file/kojenapiseraxafej.pdfIn PDF document text
    • http://www.pilatesyoga.hr/files/files/wowusamuludura.pdfIn PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/83974794689.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/serewafededov.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135dd0fce39c---dajimisavedeforababu.pdfIn PDF document text
    • http://danguykhoidoanhnghiephp.vn/Upload/files/21703330288.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/33317244373.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/jogesepigumofobika.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/3rj3uac6a8kv4kic092g3ku866/76438961146.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/sotedadorotazesowajer.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/koturadus.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/56881757007.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130855a9895c---mudigupujibu.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/begevagudepabajefiroven.pdfIn PDF document text
    • https://noventa.cz/media/files/file/fazokakaladenalulekafoper.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090116345228.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/timivirulagumusisitasit.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/43860311917.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/57033010369.pdfIn PDF document text
    • https://hiperaktivite.info/userfiles/files/ratupomapozagowixunuseno.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab43f285cb---55546404555.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=setswana+bible+free+download+pdfPDF 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_off0000e7ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7EC 10792 bytes
SHA-256: 69dfc995de4d90a58c9abfeeac178d2dd3babcb9c97359d201fd0070e623c46c
font_01_sfnt_off000100b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100B5 18172 bytes
SHA-256: 0491232dfce7cd538ac9898f49e0dda61f37ebe2742834b2d1b9aeec9c17e660
font_02_sfnt_off00013074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13074 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1