Malicious PDF — malware analysis report

Static analysis result for SHA-256 57c503fda1131676…

MALICIOUS

PDF

90.3 KB Created: 2021-09-05 10:07:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9d88331bbdd0c58168cd45fea5f58faa SHA-1: 81ec6c762b380e9adf5c403666e9d65de004f5fc SHA-256: 57c503fda11316763a48e86fffa6a22486f5e5d016f31aa2a8e83f8ccb56c53c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous external URLs pointing to potentially compromised or disposable hosting. The primary purpose appears to be directing users to external sites, which could be for phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://grawerlik.pl/userfiles/file/duvezezuloxuvumimux.pdf In PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/tosezunorosuneturujeboj.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/vofikafusamazivaboketilo.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/aedab9eaec207e347ee0eadf3e32064e/zadarusudojalovuwimaxova.pdfIn PDF document text
    • https://xn--mietkndigungsrecht-best-gpc.de/userfiles/file/wokasi.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb6f83181f---75607268801.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/wazabaxesoneba.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a634975e572---fotowuwuxemo.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160829a2505f1d---75007717554.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a697451d4ce---vowakil.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/27090169085.pdfIn PDF document text
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c97bdbc991---zafesilomoxiwoji.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/o2lf63qfl22s6d680opajcphe4/9356767778.pdfIn PDF document text
    • http://www.chubsorn.com/file/files/45249945007.pdfIn PDF document text
    • https://cordovajewelry.com/images/file/69118084314.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/27262750483.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/figami.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/5s56bg21tbfpdsbf0gn4bt6n76/9948801443.pdfIn PDF document text
    • https://perfectsextherapy.com/public_html/userfiles/file/86903275246.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-7-8/20210708074354671753.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/9848301586.pdfIn PDF document text
    • http://ocean-ex.com/images/blog/file/67510369139.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/nalabidoje.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/rebanirimun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=backplus+shiatsu+foot+massager+manualPDF 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_off0000f7b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B2 11172 bytes
SHA-256: 403458f8e1607d6888bfc9d26bc2697179a5aa9378cec4e88ccc0c44691b4992
font_01_sfnt_off000111b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111B5 18648 bytes
SHA-256: b60162ffdd1c5bfbc432b2a4ca43ba1510afe5d6f1730a2ad464fe9b6b248bbe
font_02_sfnt_off0001421e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1421E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1