Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fa9d5e5b86b55a4…

MALICIOUS

PDF

93.6 KB Created: 2021-08-18 15:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c91dcb6f808e0bc476633f688988d0ec SHA-1: 7c6a35ba492b344696edba2d712cfd386b8f3abb SHA-256: 4fa9d5e5b86b55a46490aa59eee9748926fc89dd6cdd7a30ba8e06b7a7cd734b
164 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm pointing to compromised WordPress uploads and other disposable hosting, likely to facilitate the download of further malicious content. The presence of a visual download button lure reinforces the deceptive nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://rosniyom.com/userfiles/files/88356967837.pdf
    • http://f-okinawa.com/img/tmp/file/punelogizefozasedi.pdf
    • http://prodottoitalia.eu/userfiles/files/99795686301.pdf
    • https://aplusadvance.com/naver_editor/data/file/xawus.pdf
    • https://dermatologie-francophone.com/userfiles/file/wikogusiwigopomukaket.pdf
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/e4d3c67726e7829c579558430e6a35ab/welur.pdf
    • http://banquat.com/userfiles/files/mutuxev.pdf
    • http://apexibd.com/uploads/fck_uploads/file/6669738195.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d112899381---zadotolupipo.pdf
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/918u64hje9tbdpirs5hh3ihrj0/ripuvululalime.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/bf59e52e80c82694ce694887c43ae524/fuxizozutet.pdf
    • http://aitrans.cn/UploadFile/file/F1202106220135525277.pdf
    • http://abwlondonblvd.com/uploads/files/wezipaximasavibozorokixa.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160884f3b7b966---59052357479.pdf
    • http://gdgom.com/upload/file/2107271906348856532s8umhluftkb.pdf
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/322cd5e74bf150521955378f561082eb/buxalenerupi.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/jinavebevewigedaxupelanul.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/eu7h7l8rct06oi667cc1r6k5j8/70286966606.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/7jhd80mq009k4aeuvqpcvdcb1n/deposedigutefuwegarovexig.pdf
    • http://sxcec.org/userfiles/file/94041940576.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/ef02e109aeb9ab773fff0662cd7732c1/jedizag.pdf
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/4d180772df33e6dff5628e1b1b4266fc/lajeterofitaduze.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c255ea5cd0---49604918523.pdf
    • http://cybernet.asia/UserFiles/File/gavodoj.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7830a33ff---dazifemujemewep.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=grade+7+math+module+3rd+and+4th+quarter+teacher%27s+guide
    • 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_off00010580.bin
c211a0edf140e90445787df0e8aa21d7c46062b650efe3e677f325bba724ac2e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10580 18200 bytes
font_01_sfnt_off000135b4.bin
4e05e923faf55fbd0bc5c6cf2bda14d1ea90e667a3ae909bc032891379c05daa
pdf-font-stream PDF embedded font (sfnt) at offset 0x135B4 11436 bytes
font_02_sfnt_off00015038.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15038 16792 bytes