Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57a71a882a65099…

MALICIOUS

PDF

76.9 KB Created: 2021-07-18 10:29:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 122c767d25f7f229fd46eeb382898269 SHA-1: fbe284a03d25e8a35bdb2b43ea3c775b0c14dafa SHA-256: c57a71a882a6509914622e6972a8d928994e5fb23e3a169fc1777487ea3f36f8
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress upload directories. These links likely serve as a distribution mechanism for further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160967cdb61b4d---44593493656.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16093c97c7b7b4---malitalalurinur.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e767362a910---78168937747.pdf
    • http://zulassung4you.de/bilder/file/vofesonogakaz.pdf
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/tezorilaxezupijofawupuse.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f11a5261c2---32317455554.pdf
    • http://baliretreatcenter.com/olabali_ci/media/images/newsfiles/58457508144.pdf
    • https://jerseyshorepirates.com/userfiles/files/14115362611.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/r780f4d1fmu3s343hvp6asm0l3/kanidudezefetodom.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/e33b88b542d1b0532ffd022ec47a9f25/muvufurosimosevek.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/1linnlmomtc4e9cg5u6m7hbumj/lobagozutasetigi.pdf
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/e48a906480d043fdc1e03f44c0b63f0e/43584888731.pdf
    • https://lastcallslc.com/wp-content/plugins/super-forms/uploads/php/files/a8e113f89fa71c72d7ebd75dd9c0ee6b/ramavuwobigagox.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/6fcffc3da18453bade0c6f9c8787db00/sakilowojudizi.pdf
    • http://imailbox.nl/images/uploadedimages/file/jegeboboxosudinajezenerib.pdf
    • https://cafesca.org/ckfinder/userfiles/files/sololikafoponugosiwevis.pdf
    • https://guapa2.com/admin/fck/file/88292832323.pdf
    • https://jotelek.hu/files/file/80494150599.pdf
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/1igj2ojttf581s5j0evtj0iv77/59006409688.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/e615efe66a792e786ff2ccb64a250d0c/faxujefopewufenazenoz.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bb41201007a---dobenife.pdf
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e1a4d89ce70---werotalibirukisized.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16078671be7dd0---zizuperagatigameputi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=gta+v+invincibility+phone+number
    • 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_off0000cbda.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBDA 16792 bytes
font_01_sfnt_off0000e3f1.bin
7f454478f9b0a8c368083f99c0f8a53b88ee21b5cc5d3bc6cdcf1f0cce66a054
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F1 10928 bytes
font_02_sfnt_off0000fce2.bin
841ebc1f9d8fce2d764b58f08fc9e7743889bd4621fd66478f509480a707273e
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCE2 16076 bytes