Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c0f784d1ca3d01d…

MALICIOUS

PDF

95.4 KB Created: 2021-06-27 22:05:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bc3c0a8bae15759b38834288d89a15f9 SHA-1: 0348f6433650adea5ab90428cdf6d70f8ac83e65 SHA-256: 4c0f784d1ca3d01d0087c9bfd9119cd487c26a7a709d9764ae0b0b6d50271441
164 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several pointing to compromised WordPress sites, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues about its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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 https://archism.ru/uplcv?utm_term=what+does+capasa+mean+in+spanish
    • http://oreade-breche.fr/userfiles/file/sisidopovagal.pdf
    • http://ukrainski-rosyjski.pl/userfiles/file/bevup.pdf
    • https://electrabicycles.pl/app/webroot/uploads/file/16224420777125.pdf
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/cf16e8662ec2c73ffd8385ffc3a34c03/75378487344.pdf
    • http://www.urbanwaterways.info/files/82323998179.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c1bca973e68---suminebosowakamige.pdf
    • http://teplospectr.ru/images/files/risojasukoxeruxufepo.pdf
    • http://ji-tien.com/userfiles/file/vujewu.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/009717ecbc3d85b9c6a1e51d8e48fd2e/dimiz.pdf
    • http://brukbet.com/user_images/file/valudeka.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/24adf462f5d32098f1624d9881f33306/xugamu.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b013cfd638a---53109581667.pdf
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/jdg1qtgg6n5n79o4tm81k4dn07/7409581589.pdf
    • https://larustt.com/upload/ckfinder/files/25862670375.pdf
    • http://japan-railpass.info/images/blog//file/79054004044.pdf
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad2d8ae16ac---fesif.pdf
    • http://boeschfamilytravels.com/clients/43210/File/84507473437.pdf
    • http://lorichphoto.com/pictures/file/66153536568.pdf
    • http://learningkey.org/userfiles/41978561802.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086299604dfd---jotufa.pdf
    • http://stl-hk.net/userfiles/60686249044.pdf
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000f247.bin
d9f5e66163d907df9b2c2f031b8906ab183602eda4757f3e8ef428a9cf922d60
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF247 18328 bytes
font_00_sfnt_off0000da36.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA36 16792 bytes
font_02_sfnt_off00010fdf.bin
a8161c2f5ba9235eb51b4fcc43b6bb219725019365cb8d38f9ec25dfe5ce54ff
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FDF 3464 bytes
font_03_sfnt_off00011d5a.bin
bbee0a69859e976645242bcacac78cb996d8efefd733b2dea64ef61b6d0caf3f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5A 23120 bytes
font_04_sfnt_off000155e4.bin
e91da8d620faf892cf5375fc475555f1eed2d7238bf91f3577ccdac00d83bf99
pdf-font-stream PDF embedded font (sfnt) at offset 0x155E4 10624 bytes