Malicious PDF — malware analysis report

Static analysis result for SHA-256 a88563a9c634eef8…

MALICIOUS

PDF

80.6 KB Created: 2021-09-15 17:05:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 311f9bdfc43010f8c8d81c532bf49e68 SHA-1: d137df831d5dac9a249d1aaa2e85a6653190c133 SHA-256: a88563a9c634eef8be4cb04fd0e8a1409c8504246e0129a43b5752507cc4b815
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs that point to potentially compromised websites or disposable hosting. The presence of a 'utm_term' parameter in one URL suggests a phishing or SEO manipulation attempt to lure users with search terms like 'roblox apk'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://chcial.ru/uplcv?utm_term=roblox+apk+latest+version+2021 PDF link annotation
    • https://hsdinstruments.nl/uploads/files/14552203215.pdfIn PDF document text
    • https://vcubusinesssolutions.com/userfiles/file/17947604629.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/linaz.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/05cc892525938d293c63778385d9b94b/lekojavekisukem.pdfIn PDF document text
    • http://constantemail.com/userfiles/file/1630776263kosoferemidex.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/99747acdc56f496a69377e3d71d399ce/boxupevesojumaduk.pdfIn PDF document text
    • http://naosgym.com/userfiles/files/70592878987.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/40926252954.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210915161157.pdfIn PDF document text
    • https://atputasbazes.lv/images/userfiles/files/17940885277.pdfIn PDF document text
    • http://cyklo-sport-servis.cz/UserFiles/File/36446718529.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/gokexas.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/96889833115.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/161323194e71a9---39318141133.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/f052831a1fa823d87038ecd87f91b1b2/38204069540.pdfIn PDF document text
    • http://scantech3d.com/files/valufilavutejewigaze.pdfIn PDF document text
    • https://apgr.eu/UserFiles/file/20070080264.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/xifijojo.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/notolorawu.pdfIn PDF document text
    • http://ogcdc.org/uploads/ck_upload/files/81765891225.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109140751032328.pdfIn PDF document text
    • https://robert-zauer.cz/userfiles/file/23025604022.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/wetukepot.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/purewevosalulolor.pdfIn PDF document text
    • 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_off0000d62c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62C 10984 bytes
SHA-256: b5c559d3d09c64bb90306d64728c418328c618d715f412bade48f54dc23a82db
font_01_sfnt_off0000efba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CC 17732 bytes
SHA-256: c77b821f12cda8b34b9fbaa9c86836c789774554e01e048c51238a2502a2b071