Malicious PDF — malware analysis report

Static analysis result for SHA-256 291830ad50ba8602…

MALICIOUS

PDF

84.3 KB Created: 2021-09-14 12:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b6f9dc0ce630becca31ef001cca7a3f4 SHA-1: 2d2c6f0d8f44b546a39e28e8676d1facfc57aa1c SHA-256: 291830ad50ba86022f8f7767d3da7e26749c7975935362f3ad0f18605904bae3
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan. Multiple heuristics indicate the presence of link farms pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were directly extracted, the PDF structure and numerous external links are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://pphu-joanna.pl/fckpliki/file/7661161743.pdf
    • http://hum-lucknow.org/test/fckeditor/file/tizakutumugokivekalosilu.pdf
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/sirivizesesijigi.pdf
    • http://streetnn.ru/data/upload/ck/files/runajimobigo.pdf
    • http://bm-shower.com/userfiles/files/76861095655.pdf
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/napovakigoxekutabowamel.pdf
    • https://xn--80aaijzh9b.xn--90ae/documents/file/19075337623.pdf
    • http://autoservizimensi.it/images/fck/file/43498797368.pdf
    • http://gaushalango.com/uploaded_files/userfiles/files/gixuguwiwamiwuwurunad.pdf
    • https://www.mnogotrop.com/ckfinder/userfiles/files/jojuli.pdf
    • https://apra.pl/files/file/45761043906.pdf
    • http://boston.pl/fck_pliki/file/30695638816.pdf
    • https://podereilmontaleo.it/writable/public/userfiles/file/jupopewapajudowaxe.pdf
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/a5ef1a5b045d8e39774e23d93228f4dc/mufisupexa.pdf
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/90slsvl0vqp98go7anrjjc5dj1/kanubipunataguzowotaneket.pdf
    • http://healthywithhart.com/res/file/61524818135.pdf
    • https://motodubai.com/uploaded_images/files/bimavuwusujetip.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/fpdp44g0013ht1p620jfrrvhvm/jorigajubezevu.pdf
    • https://alstar.uz/images/shared/file/fezibenotagetekiwugun.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613fedea46b02---2446715999.pdf
    • http://newabel.com/ckfinder/userfiles/files/bufodefopovalom.pdf
    • http://starfishdowney.com/uploads/files/12454014648.pdf
    • http://ambulatorioveterinariovianello.eu/userfiles/files/37704928846.pdf
    • http://radyoislam.com/resimler/files/77798096418.pdf
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/xazaxebexotej.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=silent+logging+android
    • 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_off0000e2f2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F2 16792 bytes
font_01_sfnt_off0000fb04.bin
7fa70317f5eef6333074914b48025364443d0d2d403805300152a64dcf1e136a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB04 18748 bytes
font_02_sfnt_off00012c24.bin
13eac13a4bec46f2e692f9b518e6b135fc25a282346d8cd9e89293c3d24c7d00
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C24 10328 bytes